With great gratitude to Geneva "Ginny" Birchmire
who helped in so many ways with this story
and encouraged me to feel it was worth doing.


part 1 - scavenging
part 2 - rescue
part 3 - home
part 4 - tour (diagram)
part 5 - liberate
part 6 - black
part 7 - Blossom
part 8 - foil
part 9 - people and spiders
part 10 - horses, birds, trees, ants, and slugs
part 11 - bang
part 12 - journeys
part 13 - Aimee
part 14 - cure
part 15 - contact
part 16 - Aida travels

part 1 - scavenging

I looked out over the cliff, away from what remained of the broken road. The Pacific Ocean wasn't the the blue color I remembered from my childhood. It was bright, grass-green stretching east under permanent, thick, gray cloud to the horizon. I could almost imagine it was some enormous lawn except that it glinted wetly and moved in waves, foaming as it broke on the shore, far below.

Out here in the open, the heat was oppressive, and as I lowered my gaze to the waves thundering distantly on the rocks, some sweat ran down to the tip of my nose tickling it, so I held my breath, pulled the breathing mask down, rubbed my nose with my gloved hand, then replaced the respirator again, adjusted my UV filtering goggles to make sure they stayed airtight, and pulled my wide-brimmed hat down a bit to make sure I was still properly protected.

Jill was standing beside me. I heard her voice crisply in my earphone, "I was reading an old article recently that said this is where it started." Without her mask's microphone, her voice would have been muffled. I glanced at her.

Of course there was only one thing it could be. I waved my arm to the left — north. "The first sighting I heard of was way up near Rockhampton." But really, with seventy percent of the world being ocean, it could have been anywhere. The place that people first noticed it didn't really matter.

I turned my attention back to the road. It was impassable. Part of the hillside had long since slipped away, taking most of the paved surface with it. We could get by on foot, but we'd have to leave the car here. I didn't need to say anything. Jill could see what I was thinking. She shook her head, "No way, girl. It's too dangerous. We might not have enough air to walk that far and back. We can return another day and find a safe road."

I shrugged. "Or find a more accessible town."

Jill walked back to the car. It was an old, small, Tesla two-door hatch-back with darkened windows. It was towing a trailer, onto which we'd already tied a number of good finds earlier today. Long ago we'd put much larger wheels on the car and trailer to raise them higher for better ground clearance. The unmaintained roads would have been impossible to travel on the original wheels. Travel was more difficult every year as vicious storms tore away at the hills, competing against the fast-growing vegetation to see which could break up the roads more quickly. Many roads were now undriveable... probably most were now.

Jill turned the electric car around, noiseless except for the crunch of the tires on the loose detritus — mostly small rocks and pebbles from the gradually eroding high side of the road. She paused for me to get in. I fastened my seat belt, taking care not to constrict my respirator tube, and took off my hat while she drove back the way we came.

After a minute she said, "I vote we go home."

That was fine by me. "Might as well, we've already got some good stuff."

She said, "Depressing out here. It always reminds me of how much we lost."

I just nodded, feeling glum.

After a few more minutes of driving, Jill experimentally lifted her mask and sniffed, then, stopping the car in the middle of the road, pulled her mask and dark goggles off, and removed her earphone. I did the same and switched off our hip-mounted air cylinders and radios. Then I reached behind the seats to the car's large air canister and turned it down to a trickle, now that it had fixed the air in here.

We drove in silence for about quarter of an hour.

Jill gave a deep sigh and said, "I hate it out here. The sun is what I miss the most — being able to expose skin and look around without UV filters. I'll be glad to get back home and take off all this damn clothing. It's too hot and restrictive."

"I miss the birds." I sighed. "It's all so quiet and still without them. This monotonous green everywhere gets to me sometimes too. Birds added color."

"The flowers too. Now even they're disappearing. The acid rain, perhaps?"

I nodded. "Mmm... and no seasons — just hot and dim all the time."

That didn't exactly cheer either of us up. We had a couple of hours' drive ahead of us to get home. We spoke little on the way, both of us wrapped in our thoughts.

We wound our way westward from the coast toward the range that separated it from the hinterland. I looked through the car window's tinted glass at the hostile world as it slid past, sometimes glimpsing, through the trees, the remnants of houses being slowly consumed by vegetation, forests covering what was once open grassy paddock. These roads used to be bright and open. Now, mostly overshadowed by tall, dark trees, they'd become like tunnels through forest, and the perpetually overcast sky worsened the gloom. It deepened my mood still further, and as I did far too often these days, I remembered what my parents used to say.

I was only eleven years old when everything changed, so I don't remember much about the time before. Most of what I know about it comes from books and movies. Mum and Dad often used to talk about it. They said everybody always assumed that the greatest dangers were war, overpopulation, climate change, and ecological collapse, but that we would solve them when we really needed to; human ingenuity could survive anything. Who would have thought that the end of human civilisation would be brought about by a tiny, single-celled plant? It isn't even poisonous. The great danger it presents is that it is more efficient than other plants. The grand and arrogant human species killed off by a microscopic plant! Well, almost killed off. Jill and I were still here, hanging on by our fingernails, but humankind's planet-wide civilisation, all our wondrous technology, our giant, sprawling cities... all silent, decaying now. And we stragglers would follow soon enough.

We humans had thought we were the pinacle of life; a thousand different religions crowning us as their god's special creature, made in his image. Many people thought that we occupied the top-most branch of the tree of life, that we were the culmination of evolution, the cleverest ape, never realising we were merely one of billions of aimless experiments that went nowhere; a dead end. For all our puffed-up self-importance, we were always just a blink, a momentary twitch in the vast continuum that is the universe — a universe that had no interest in whether we lived or died.

Even though this mutant alga brought about the conditions that ended civilisation, we couldn't entirely blame it. Humanity died due to an inability to deal with exponential change. We had already been already filling the atmosphere up with carbon dioxide and bringing about climate change. People had known about that for more than fifty years before many started to really admit global warming was a genuine threat. The politicians, even when they did grudgingly begin to acknowledge it, still refused to make any genuine changes. So when marine biologists found these mutant, quickly-growing, single-celled algae nobody really thought much of it, other than the scientists. At first it seemed a very useful thing. Growing algae industrially to generate diesel fuel had become economically important, and being able to use a super-efficient form that multiplied like crazy was too good to pass up. It took many years for warnings from scientists to percolate through to the mainstream media. All photosynthesising plants use the energy of light to split carbon dioxide into oxygen and carbon, then add that to water to build hydrocarbons (fats and oils) and carbohydrates (sugars, starch, cellulose, and wood). Other plants discarded some of the oxygen as a waste product, but these algae didn't. Oxygen is very reactive, giving off lots of energy in the process, and instead of discarding it, these mutant algae used that extra oxygen to power their own metabolism still further. This gradually became a problem for the entire animal kingdom, which needed oxygen to survive.

For most people the warning fell on deaf ears. So what? they would say. These algae are really tiny, and there are plenty of other plants that still give off oxygen, and the atmosphere is really, really big.

Climate change continued to be an accelerating problem. People eventually made big reductions to their carbon dioxide emissions (not the politicians though, they always seemed to be two steps behind). But climate scientists found that the concentration of carbon dioxide in the atmosphere was still increasing. Of course the climate change deniers were delighted by this, saying that they'd told us all along that humans weren't causing climate change. This was a point of confusion for a while, because the maths had shown incontrovertibly that we were the main force driving carbon dioxide levels. And then the change in the color of the oceans became obvious. They started to become grass-green.

Most non-scientists were under the impression that the trees in forests were the most important source of oxygen on Earth, but they were wrong; trees were merely a secondary source. The main source of oxygen was always the algae in the oceans, and this new species had been out-competing them at an exponential rate. With the oxygen-producing algae in the ocean out of action, oxygen began to be depleted from the atmosphere, and carbon dioxide continued to accumulate, being breathed out by all living things that were not plants — all the people, cattle, birds, fish, insects, protozoa, bacteria, fungi — they were all using up the remaining oxygen and replacing it with carbon dioxide. Add to that the remaining coal- and gas-fired power stations, all the fires lit for cooking and to clear forests, and all the internal combustion engines — all the cars, trucks, motorcycles, chainsaws, steam and diesel trains, ships, airplanes, water pumps, leaf-blowers, lawnmowers. We were speeding toward extinction and most of us had no clue it was even happening. Of those who were warned, most ignored it, either thinking we still had plenty of time or simply denying that it was even a problem.

I never understood why people would deny reality. I would ask Mum and Dad why people would ignore evidence, but they didn't understand it either. Dad was a botanist and Mum was a computer programmer. Mum had some understanding of the human mind because of her work on designing artificial intelligence systems, but was still powerless to explain people's rigid beliefs in things that were obviously wrong. One of my early memories is her embarrassed smile and helpless shrug when I found out that some people believed in gods — not just one god, but hundreds of them — and that they believed all kinds of nonsense based on nothing more than absurd old writings by superstitious bumpkins. I was horrified when I found out they would even kill each other for their imaginary gods.

But I also came to appreciate how the human mind could be a marvellous thing. Mum taught me how to write amazing computer programs and to design electronics and pneumatics that automate systems where we lived and worked. Dad showed me how to use the electron microscope, the mass spectrometer, how to run the PCR machine, and how to operate all the other equipment in the lab where he worked, and he taught me about the structure and biochemistry of living cells and why they functioned. Other people at the Habitat project taught me about animal husbandry, some architectural engineering, some astrophysics and planetary chemistry, and Alice, the psychologist, taught me a lot of psychology. But even she was unable to explain why people would cling to unreality. When I would ask her, as I did many times after reading about people's inexplicable beliefs and actions in books or after watching them in movies, she was fond of saying that I had the question backwards; the puzzle is not that people were so out of step with reality, but that this jelly-like mass, this self-growing electrical network of cells we call our brain, could understand reality at all.

I had what I consider to be the perfect childhood. I was very lucky because not only did I learn almost everything I would need, but I lived in the perfect place to survive what was to come.

The end came terrifyingly quickly. For years the air seemed to hardly change. There was no real sense that carbon dioxide and oxygen levels were shifting in opposite directions at an exponential rate. An exponential curve always starts slowly until it reaches an elbow then unexpectedly shoots off the chart. And that's what happened. Suddenly, in just days, oxygen went from levels that made heavy exercise uncomfortable, to suffocation. This was exponential change. Nobody was prepared, mostly ignoring or denying the problem right up to the last day. The scale of death was unimaginable. Billions of people and all the animals died. The birds survived longest because many of them were much more efficient than other animals at extracting oxygen from the air, but eventually they died too. Only the plants and anaerobic bacteria survived.

It used to make me angry, but it doesn't anymore because now I realise it had to be this way. It was inevitable. At least we had our time, against all odds... our brief window... maybe two hundred thousand years as humans, the last few thousand building civilisations, and the last couple of hundred years creating amazing technology, then suddenly, gone. We were an invisible footnote — invisible because soon there will be nobody left to see it, no animals at all, no eyes... just vegetation. A green, mindless planet, soaking up the sunlight, until the planet is sterilised when the sun expands in another billion years. And then the sun itself will die in about ten billion years. It's just an average star — just one of an estimated 250 billion in our galaxy, the Milky Way, that pale cloudy band that used to stretch across a clear night's sky when I was young. Now the sky is permanently overcast with thick clouds. Out beyond our galaxy there are more than 100 billion galaxies that could be seen by astronomers' most powerful telescopes — each one of those galaxies containing billions of stars, and most of those stars orbited by planets. So, looked at in the greater scheme of things our disaster hardly matters. We had our time and it passed.

Jill and I sometimes wondered if anyone else survived the catastrophe, but as far as we knew, we two were all that remained, just marking time, and we would eventually die of old age, or earlier if our equipment failed or we had an accident. I saw our situation as hopeless... no future, only the present. So that's where we tried to live: in the present. Alone.

Jill, perhaps sensing the bleak turn of my thoughts, glanced at me, "Never mind. We found all those flash drives today. I bet we'll find some movies on some of them, maybe even a good comedy..."

I tried to force a smile. She was right. We'd scavenged some good things today. "The rolls of cloth were a good score too."

"Bolts," she said

I looked equiringly at her.

"The rolls of cloth. They're called bolts."

I smiled more genuinely now. Odd word to use for textiles.

We were driving up what remained of the steep road to what used to be the town of Mapleton at the top of the range and she looked up at the constant clouds now darkening, "If we can get them home before it rains." They were at risk, on the trailer, exposed to the weather.

"Doesn't feel like it'll rain." This altitude gave a good view, relatively unrestricted by trees, so I turned in my seat to look down over the vista of the coastal land to see if rain was coming. It would most likely come from the east, behind us. "Doesn't look like--" I broke off suddenly. "Stop the car! Stop! Stop!"

The car's electric hum fell silent and Jill turned to look at the trailer, but when she saw me rummaging in the bag at my feet, then pulling out the binoculars she squinted into the distance and she saw it too. She drew breath sharply when she spotted it. Far south on the coast was a thin wisp of smoke.

"Do we have enough air?" she asked.

"It'll be cutting it close, but we can travel faster if we leave the trailer."

She nodded and resumed driving until we found an accessible house with a carport where the trailer and its contents would be safe from any rain. The structure was heavily covered in creepers, but relatively intact, sheltered by the large, heavy trees around it. Jill carefully backed the trailer under the carport. For the umpteenth time I was thankful for the remote-unhitching mechanism that saved us having to get out of the car and waste more air, then we took off as fast as we could safely drive in the direction of the smoke.

There was no question of whether we should do this. The smoke definitely meant people because the atmosphere couldn't support fire anymore. Only humans, maintaining small, oxygenated living environments, could make fire possible. And oxygen was so valuable now that surely nobody in their right mind would waste it on a fire. That almost certainly meant someone was in trouble. It had been nearly twenty years since either of us had seen another live person. We were both hoping we could get there in time to help.

* * *

part 2 - rescue

The roads were a problem. Each year they became more broken. It was just sheer luck we only encountered two fallen trees along the way and both those were easy to drive around. We made very good time, all things considered. The source of the smoke was a warehouse just north of Caloundra. As we drove closer I turned on my air tank, donned my mask and goggles and earphone. I switched my radio on and Jill pushed her earphone into her ear.

I said, "You stay in the car. I'll check it out and make sure it's safe."

"Okay," she said into her mask while pulling its straps over her head. Her voice sounded tinny in the receiver in my ear.

The warehouse was large and gray and I couldn't see any windows, so I pushed my goggles up onto my forehead, pulled my bag up onto my lap and got my torch out. I was about to put the bag back down and on impulse grabbed my Swiss Army penknife too and pocketed it, then dropped the bag to the floor again.

Jill nodded, her mask and goggles on, ready for me to open the door.

I pulled my goggles down again, donned my hat and gloves, and got out of the car as quickly as possible so as to minimise loss of its oxygen.

As I approached the warehouse I could see the main large door had been welded closed. That might be a good sign. Perhaps someone had tried to make it airtight. It was hard to tell how long ago the welding had been done. With very little oxygen left in the air iron didn't rust very quickly anymore. I explained my observations and thoughts to Jill over the radio while I looked for another door. There was an alley beside the warehouse and an old car was parked halfway down the alley beside a smaller door. Time was pressing so I trotted down to the door and tried it. It was unlocked so I opened it just enough to slip in and closed it carefully behind me. I flipped up the filters on my goggles while looking around the dim interior and pulled my breathing mask down for a moment to cautiously sniff the air. Rich carbon dioxide stung my nose so I replaced the mask again, telling Jill.

The smoke was probably coming from a room at the back so I strode quickly to the back door and tried it carefully. It was unlocked so I opened it slightly intending to slip quickly in, but what I saw made me shut it again quickly, but gently, quietly, and back away from it in horror. In whispers, I described what I'd seen to Jill. About five or six meters away from the door a large man had been facing away from me cutting up a human body hung from hooks, while on the floor near the door a woman in a shapeless, dirty, gray dress lay tied up, and on the other side of the man was what looked like some kind of stove, on which meat was sizzling and sputtering. Jill pleaded with me to leave, but I couldn't.

"If that woman is alive I can't leave her to a cannibal."

Jill sounded more upset than me, "But what can you do? If he's big you could be hurt or even die. Please don't. You don't even know if she's alive. You might be risking your life for someone who's already dead. Now is not the time to be a hero."

I sighed. I could feel it happening to me. When I'm in an emergency it feels like time passes more slowly for me and I become very calm. I said to Jill, "If not now, then when?" I used the torch to look around the large, dark, dusty warehouse for something I could use to keep me safe. My penknife wouldn't be much use as a weapon. There did't seem to be anything. I was wracking my brains for some kind of plan and coming up as empty as the warehouse interior.

It would be too dangerous to engage him directly. There was only one thing I could think of, so I went back to the door. Carefully, quickly, I opened it just enough to slip silently inside, then immediately, quietly, closed it again behind me.

The man still had his back to me and was still busy with his gruesome cooking, which hissed, crackled, and sputtered loudly before him. There was a diving mask and aqualung tank on the floor near the door. It must have been what he used to come here.

I bent to the woman. She was alive and was now raising herself to a sitting position. Her legs weren't bound. I raised a finger before my breathing mask in signal for her to be silent. She nodded and I pulled the gag away from her mouth while throwing quick glances back to the big guy who was was still involved with his noisy, ghoulish work. I helped her to her feet, her wide eyes fixed on the man's back.

When we got to the door I grabbed the mask that was sitting atop the scuba tank there, pushed the strap quickly over her head, making sure it was seated firmly on her face and turned the air on. I lifted the tank, which was heavier than I expected and almost dropped it while balancing it on one hip with one arm as I reached for the door handle with the other hand. We slipped out the door, which I shut quietly behind me.

I put my head near hers and said just loud enough that she could hear, "Can you run?"

She nodded. We ran awkwardly, her with her arms still bound behind her, she padding along on bare feet, and me holding the heavy scuba cylinder, heading back out the way I'd come while I told Jill over the radio what was happening. Outside, I stopped by the old car and asked her, "Did he come here in this?"


I put the air cylinder down, pulled my penknife from my pocket and stabbed the valve stem of one of the front tires. The tire deflated with a loud hissing sound. I was expecting the man to burst out of the warehouse behind us any second, so I quickly closed and pocketed the penknife, lifted the tank again, and we ran back up the alley to where Jill was waiting for us, having already turned our car around for a quick escape. I opened the hatchback of the car and helped the woman in to hurriedly lie on top of the stuff there, putting the air tank in with her. Then I slammed the hatch shut and jumped into the passenger seat, and Jill accelerated our little car out of there, like a bat out of hell while I was closing my door. I got my penknife out again, turned in my seat, leaned into the back of the car and cut the woman's bonds. Her arms were red and purple-bruised and she started rubbing them.

I told her, "Give it a few minutes and the air in here will be okay. Then we can all remove these masks."

She nodded.

After a few minutes I lowered my mask and carefully sniffed. "Okay." Both Jill and I removed our masks and goggles. I turned our air bottles off and turned the car's air feed down.

When I turned and looked, the woman in the back had removed her mask and turned the aqualung tank off.

She said, "Thank you. You saved my life."

"You're welcome. This is Jill and I'm Kim."

"I'm Michelle.

I noticed I was starting to tremble. The emergency had passed, so now my body was catching up. I was glad Jill was driving. I needed to distract myself with conversation. "What the hell was going on back there?"

"I was going to become a meal."

Jill frowned and shook her head in amazement. "What kind of idiot kills another person? People are too rare and precious. It doesn't make any sense to use them as food."

The woman said, "Not where I've been living. I'm too old to breed and not as attractive as the younger women. I'm just a drain on resources."

Turning and looking at her more carefully now, I saw she was a similar age to Jill and myself — about 50 or 60. She looked fit, though a bit thin under the grime; her messy, drab hair was dark, either black or dark brown.

I told her, "We have to get home in a hurry as we're running low on oxygen. Is there somewhere you'd like to be taken?"

She shook her head and asked, a slight note of pleading in her voice, "Can I come with you two?"

I looked at Jill, raising my eyebrows in question. She glanced sideways at me and said, "Of course!" I smiled and Michelle breathed out a huge sigh of relief.

We drove as quickly as possible without taking risks, back toward the mountains, and when I asked her where she came from she explained:

"My family moved from the Gold Coast up to the Sunshine Coast when I left Primary School. I had been in my first year of High School in Caloundra when the catastrophe struck. My parents were enthusiastic scuba divers and had become owners of one of the diving gear suppliers on the coast. Their familiarity with the sea and friendship with many marine biologists meant they'd seen what was coming. They'd installed off-grid solar power and completely sealed our home and the warehouse.

"They'd taken in eight friends and their immediate families to survive the catastrophe. But some of them were not nice people and soon took command of the group, ruling by force and killing those who disagreed, including my parents. These monsters granted themselves absolute privilege over everybody else and took women and girls they wanted as breeding partners. Others were allowed to remain alive as slaves. We survive on canned and dried foods mostly scavenging from supermarkets and supermarket warehouses. Babies born from systematic raping become slaves too. Older women and men, when they outlive their usefulness become meat. There aren't any animals, other than people, and these bullies are always hungry for meat."

She fell silent for a while then. I wondered if she was either thinking about earlier people lost this way or remembering how close she came to that fate. I spoke to pull her mind away from the discomfort. "We're vegetarian, but we do have eggs laid by our chickens."

Her eyes lit up. "Birds?"

"Yes. They're pets, really. We have other birds too. They keep the gardens healthy by stopping any build up of pests."

She gasped, "You have food plants? We tried growing food, but seeds didn't breed true or else grew plants that were sterile. And they, and any fruits they produced, were very woody and stringy anyway — not much good to eat."

Jill said, "That's the carbon dioxide-rich air. It makes plants grow a lot more woody. We grow our plants inside. And the problem with most seeds from before the catastrophe is that a lot of companies deliberately sold F1 hybrids — plants that were either sterile or whose next generation was different from the parent, generally not as good. It was done to lock customers into buying more seed. I never understood why it didn't just make people never buy from them again. Our plants are reliable — they were called heritage seeds."

I asked, "How do you get your oxygen if you don't have plants inside?"

Michelle said, "Oh, there's still oxygen in the outside air, just not enough to breathe. We have machinery to extract it."

"Ah. Oxygen concentrators." Jill said. "We have some for emergency use." Jill glanced at my blank expression, "Remember? The salvage team got them from the hospital soon after the catastrophe. We've never needed to use them."

I didn't remember.

Michelle's voice grew excited again. "Team? How many more of you are there?"

I took a deep breath and let it out in a big sigh. "Unfortunately we're all that's left. Some of the team died of old age, though most died in accidents... usually when out scavenging. Some others when part of the habitat failed."


"Where we live was part of a scientific experiment. Have you heard of the Biosphere 2 Project in USA?"

She shook her head.

"It was a large, sealed building covering about three acres — they wanted to make completely self-sustaining ecologies with a team of people inside for two years. Nothing, not even air, got in or out; only light, heat, and electricity. It was often reported in the popular press to be a failure, but it was actually a great success. Enormous amounts were learned from it. It inspired the Habitat project our parents worked on. They were investigating how to build long-term sustainable ecosystems for Mars, the Moon, and elsewhere in space." I stopped speaking, lost for a few moments in the memories of those happy days with our parents and friends. While building and maintaining the Habitat, they'd often tell me of their dreams of human space travel and settlements on other worlds. Those days were so buoyant with optimism — there seemed no limit to what humanity was capable of achieving.

Probably noticing my distractedness, Jill said, "Unfortunately the catastrophe occurred. We'll never know if space could have been colonised, but we've certainly proved that our habitat is sustainable. Until today we thought we were probably alone... that nobody else had survived. Running the Habitat properly is quite complicated. It's difficult to keep everything in balance. As far as we know there was no other project like it at the time of the catastrophe, so we figured everybody else had... died."

I said, "You're the first other person we've seen in about twenty years. It's so hard to believe you're here. And if you survived, how many more people must there be? Each must think they're the only ones."

Michelle nodded, "We thought we were the only survivors too. We never saw anybody else. I always wondered if that might be why the bullies took over. If they knew there was still some civilisation still out there they might be less cruel."

We lapsed into silence for some time, each lost in our own thoughts, and stared at the road through the tunnel of vegetation. All the trees crowded out any long distance view to either side. We could only see any great distance ahead and behind. Occasionally we had to slow and drive carefully around shrubs or grass tussocks replacing the road and the fallen trees we'd encountered on our way here earlier. It was strange. I'd have thought we would have talked endlessly. We certainly had plenty to talk about. But we sat quietly for much of the drive, enclosed in our own minds. Jill and I tended not to talk a lot on field trips anyway. Maybe that was it: we didn't need to talk much and perhaps Michelle felt this and fell into step.

Finally I stirred and broke the quiet when we were approaching the top of the range at Mapleton. I turned, looked out the rear of the car and pointed to the faint, spindly trace of smoke in the distance. "That's how we realised you were there. It's harder to see now than before. You were very lucky. Some hours earlier or later, or a different day and there wouldn't have been anything to see. We wouldn't have known." I could see Michelle's jaw tighten. It was obviously not a marker for happy memories.

Jill said, "Just up here is where we left the trailer. We'll re-attach it and continue on home."

The overgrown house with the carport was easy to find. Jill reversed the car expertly to the trailer. Then, using the rear video camera, carefully lined up the link between the trailer and the car. She pressed the dash switch for the locking mechanism, there was a satisfying clunk, and we were off toward home again.

I noted the time on the car's display. "We'll get home just before dark if the road isn't blocked by fallen trees or branches and the weather holds."

Michelle asked, "How much further to go?"

"About an hour. Do you know where Brooloo was?"

She shook her head, so I displayed the map on the car's central dash panel. I widened the view to include Caloundra. "We're in the center of the map. Here is where you were." I pointed to the industrial district outside Caloundra. "At the moment, we're in Mapleton on top of the range. We'll go down the other side of the range into the Obi Obi valley, past Kenilworth, out over the next mountains, and down into those valleys, there. See Brooloo?" I pointed out the name on the map. "Our home is a little way before there."

Jill said, "The Habitat designers chose the location because it was close enough to services to keep costs down, yet far enough from cities to avoid it becoming a tourist attraction. After so much bad publicity in the mainstream media for the Biosphere 2 project, the funders of our Habitat wanted to keep a low profile. When the catastrophe hit we thought we would have people beating our doors down, but nobody knew about us except the scientists actually working on it and a few business people. The financers were unable to get to the Habitat because internal combustion engines no longer worked reliably, so no cars or airplanes. And coal fired power stations had failed so electric trains stopped too, not that there were electric trains out there, anyway — diesel engine and coal-burning steam trains only."

Out the western side of Mapleton now, we started down the "up" road marked by a big "GO BACK WRONG WAY" sign now almost obscured by vegetation. The unsealed "down" road had become impassable years ago with the year round torrential downpours which the changes in climate had brought. The sealed "up" road had managed better, but was starting to look worse for wear too. This morning we'd had to get out of the car to move rocks and rubble from one spot that had slipped onto the road, and another part had fallen away, taking some of the road. It would not remain usable for much longer. We would have to take the long way around then. Not for the first time, I found myself thinking what a pity it was that we hadn't been able to save any horses in the Habitat. A horse with a breathing mask on would make a much better form of transport — slower, but able to negotiate rough terrain. But all those beautiful horses were extinct now, along with virtually all other animal life on Earth.

When we reached the valley at the bottom of the range, Jill slowed for the first bridge. It was still holding up well. Since all the forests had regrown they'd lessened the flooding, soaking up the massive downpours and releasing them slowly over longer periods. The Obi Obi creek rarely flooded badly anymore the way it used to. And with forests all the way to the coast, the "conveyer-belt effect", where rain that fell on forest evaporated to fall again further inland, meant that the dry inland of Australia was greening. Perhaps one day there would be an inland sea once more, without oxygen to burn the forests... and without humans to light the fires and to cut down and bulldoze the forests.

Travelling through the tall, dark forests shadowing the road through the valley I began to worry that we wouldn't make it back before dark. It was dangerous to travel at more than a slow crawl at night because of the risk of holes in the road and fallen trees, and we didn't have much air because of our detour and extra passenger. If we now had an accident that delayed us by an hour we were as good as dead. We would never reach home.

Perhaps I was frowning or fidgeting. Jill said, "Don't worry, we'll make it in time." But I didn't start to relax until we reached the crest of the next set of mountains the other side of Kenilworth. Ahead of us was the beginning of a beautiful, deep red sunset. Not far to go now.

* * *

part 3 - home

Eventually, the car's headlights revealing our way, we drove through the gates and along the wide, sealed driveway that snaked through silhouetted trees toward the left edge of a large, low, domed building. The building sensed the car, opened the garage door automatically and turned on the entry lights. When we were inside, the door closed behind us and we drove down the inclined tunnel, gradually curving to the right. After a little more than 300 meters another door opened, allowing us to emerge into the large, high-ceilinged garage. I said, "We're about thirty meters underground here."

Jill parked near one of the few interior doors. I pointed to the green light next to it. "That green light means the oxygen in here is okay. If there is ever too much carbon dioxide here it turns red and flashes."

Opening the car door, I said as I got out, "Leave everything in the car. We'll come back later for it. Masks and air tanks stay here too. I'll refill the tanks later."

Moods were much lighter now we were safely home, and Jill grinned, "I'll bring the computer stuff so I can look through them while you prepare dinner."

I explained to Michelle, "Whoever drives the car doesn't have to cook."

Jill said, "Although, what Kim does can't really be described as cooking."

I raised an eyebrow, "Does that mean you don't want any?"

Jill turned to Michelle and said with over emphasised care, "What I meant to say, is that Kim is a wonderful cook."

Michelle laughed at our banter.

Jill chuckled and said, "Don't laugh yet. We have to be decontaminated before we enter the Habitat to prevent spores of the algae getting in."

All traces of my earlier gloomy mood gone now, I said to Jill, "Ya big baby." Then I turned to Michelle, "Don't worry. Decontamination is easy. Just follow me, and avoid looking directly at the purple lights. They're ultraviolet and can hurt your eyes."

I beckoned Michelle to the entry door, opened it to the anteroom filled with strong purple light, giving our teeth and whites of our eyes an odd glow. I said "I hope you aren't modest. We have to undress to shower and go out the other side. Put your clothes in here." I pointed to the chute.

I took off my gloves and shoes, stripped off my clothes, and explained, "It's very important to wash thoroughly, especially hair, feet, under fingernails and all exposed and unexposed skin. We can't afford any of the rogue algae getting into the Habitat." Then I stepped through the sliding glass door into the shower to wash thoroughly with soap under the hot, pressurised water.

When I was done, I exited through the sliding door on the other side to a towel and white coveralls and slippers.

Michelle came through soon. When she stepped out, dripping wet, she had a big smile on her now rosy-cheeked face. "I'd forgotten how great a hot shower feels. That was absolutely wonderful!"

We left Jill to follow. She would put the scavenged drives in the UV steriliser, where they'd be subjected to very high intensity ultraviolet light and strong air blasts in combination with ultrasound to shake particles loose. Then she would shower too, but by then we'd already left and climbed the stairs up to the living quarters. We could take the lift, but unless I was excessively tired I always preferred the stairs.

When I opened the door to the living area and Michelle saw what lay beyond, she just stopped and stared, then walked forward, her mouth open in awe.

The living area was fairly large — a kind of lounge-dining-recreation area with a kitchen corner off to the right side. It was well lit, though not brightly so. Several meters of wall to the left of the kitchen area was floor-to-ceiling glass doors. She walked slowly into the living area, looking like she'd stumbled into a palace. Then her attention was caught by what was beyond the glass doors. In the final, dimming, deep red glow of the cloud-obscured sunset the hundreds of clear panels of the high dome could be seen, and under that, in deepening darkness were the silhouettes of trees.

This all seemed quite ordinary to me. I'd lived here since I was a child. I knew it was beautiful and I loved it, but my close familiarity had made me take it rather for granted. I saw the stain on the carpet near the door where a puppy vomit had never completely cleaned off, a rough part of one of the lounge chairs where Nubi the goat had chewed it when she was a kid, the steam damage to the wall above the stove, the hand marks and animal nose-prints on the glass. Seeing it suddenly from Michelle's point of view made me proud of it all; let me see it anew for the superbly designed, cleanly efficient, and luxurious place it was.

Michelle sighed in awe, and as soon as she did, barking erupted from an adjoining room and Gina and Toby came racing out. As soon as she saw me Gina stopped barking and came to me wagging her tail and wearing a big embarrassed doggy grin. Toby went straight to Michelle, interested in the miraculous appearance of a new human.

"Don't worry, Toby won't bother you. He's a sweetie pie. They both are." I squatted and hugged Gina, murmuring "Aren't you, honey" to her and got a big slobbery lick across the face in response. I stood again, wiping my face with my forearm, and indicated Michelle. "Gina and Toby, this is Michelle. Say hello."

Gina padded the few steps to Michelle and wagged her tail reassuringly. Toby stood nearby her, with a less enthusiastic wag of his tail — polite acknowledgement.

Michelle tentatively reached down and touched Gina. At first very timidly, but slowly gaining confidence. By the time Jill came in she was patting Gina almost at ease.

I said, "Okay. Make yourself comfortable. I'll get started on dinner. Is there anything you don't eat, Michelle? We're mostly vegetarian here, with some eggs or some fish once a week."

Michelle shrugged. "I don't even remember what fresh food tastes like. It's been so long — decades. I'm sure I'll enjoy whatever you cook up. It'll be great to eat real food again, thank you."

Jill beckoned her, "I'll show you the bedrooms and you can choose whichever one you'd like."

They left and I started preparing a dinner of mostly root vegetables: carrots, potato, and yellow sweet potato. Preparation was simple. From the larder next to the kitchen area I retrieved the pre-washed tubers, cut them up, and put them into the ceramic bowls — now three instead of two. (Just seeing the increased number of bowls put a smile on my face.) Then, taking a bigger plastic bowl, went into the larder again, with my foot pushed aside the freezer door set in the floor of an alcove, and walked down the steps. Inside the freezer room now, my breath misting before me, I grabbed a handful of snap-frozen spinach leaves, selected some broccoli florets, a scoop of sweet corn loose off the cob, a scoop of peas, and a couple of handfuls of tomato pieces, putting them all in the bowl to carry them out again. The cold was nipping at my fingers. I looked around to see if anything else suggested itself. We'd accumulated a lot of excess food over the years, with just two of us living here. We were reluctant to scale back the gardens more than we had. Maintaining a surplus meant that we had a large safety margin of food in case there was another accident with the Habitat (the last big accident had been about twenty years ago). Being extremely well insulated, the freezer used very little energy, and because it used a stack of solid-state peltier devices powered by solar cells — no moving parts — it would probably run reliably for hundreds of years.

Unlike Jill, I was a very uncreative cook. I could look all day at the shelves stacked with containers and still be unable to think of anything else to use in the dinner so after another cursory glance around I walked back up and out of the freezer. Its light turned itself off behind me and the door slid shut as I stepped up to the warmer air of the larder again.

Back in the kitchen area, I divided the frozen food among the dinner bowls, which I then put into the microwave oven. I wasn't sure how much time to allow for cooking the additional food, but I'd check the progress after about thirty minutes.

Jill had left the drives we'd scavenged today on the low table in the lounge area, so I went to have a look at them. A several petabyte drive was among them, so I picked it up, took it over to the little box we used as the entertainment hub, and plugged it in. The computer woke up, turned on the large screen immediately, and began displaying the contents of the new drive, searching automatically for ebooks, music, and video files. I raised my eyebrows in surprise at the long and growing list it displayed. I eagerly scrolled through the titles.

I was still exploring the drive's contents about ten minutes later when, accompanied by the two dogs, Jill and Michelle strolled back into the room talking about the way the picture windows in the bedrooms work. I turned to them and pointed to the screen. "Jackpot. Whoever owned this drive was a dedicated collector of movies, documentaries, TV shows, YouTube videos, talks and music from the internet. There are hundreds of thousands here."

Jill rubbed her hands together, "Oh good. An enthusiastic filesharer. Thank goodness for them. Hard to believe people tried to make it illegal to share things back in those days. Leave it plugged in, to let the computer back it up into our storage in case this drive fails. Goodness knows how old it is or how much it was used."

I sat in one of the lounge chairs, "Dinner'll be ready soon. Michelle, do you feel like telling us more about the group you come from? Or would you prefer to leave it until later? We can watch a movie instead, if you'd like. It's just... maybe we could help more of the people there — though not the bullies, of course."

Jill added, "We have lots of room for more people. You'll be surprised how much when you see everything tomorrow in the daylight."

Michelle frowned and looked down at her hands, counting on her fingers. After a little while she looked up and said uncertainly, "There are twenty three people there, not counting the six who are the main tough guys and three more who are their women. It would be asking for trouble to bring those nine here. How can you have room for twenty three people?"

Jill looked surprised. Her look probably mirrored my expression. Twenty three!

Jill said, "Wow! Amazing that thirty people could live for fifty years on supermarket warehouse stocks."

Michelle shook her head. "No, the group started quite small. Then after the bullies took control they reduced numbers even further by killing some people, like my parents. The increase is from children born from systematic raping. And we don't eat very well. The bosses do, but the rest of us don't."

I wondered, "How much longer is their food going to last? It must be starting to run low by now. Unless we get those people out of there they will all eventually starve to death."

"Or fall to cannibalism," Jill winced.

I frowned, "Accommodating another twenty three people won't be easy."

Jill said, "Maybe we could build onto the Habitat."

It might be possible. A few scenarios quickly played out in my head. "We could try making a separate structure, then it could be connected to the main Habitat after it's built and sterilised, to get rid of any algal spores... I'm not sure how we'd sterilise something that large." I started thinking about the materials we would need. It would be a big job, but with the extra hands it might be done.

Jill was nodding slowly. "We'd need to teach the new residents a lot, but children learn very quickly, and with more people some things become a lot easier and quicker. Even so, it could take a long time."

I was starting to see some structures in my mind's eye. "Maybe we could design it to operate in stages... maybe as a lengthening cylinder with each added part becoming functional as we build onto it. I'll try drawing up some ideas later." I shook my head. "I need to work out where we'd get the materials from too. We can make some here, but..."

We all fell silent for a while, pondering.

Jill turned to Michelle, "Next problem: how? How do we get them away from the thugs?"

"Many times I dreamed about getting away from there and how to do it, but there was never anywhere to run to. The bullies don't feel the need to guard against escape. After all, where would anybody go?"

Jill smiled, "There's our advantage. That, and the fact that they won't be expecting us."

I shook my head, "We helped Michelle escape. That will have alerted them."

Michelle disagreed, "No. Herman never saw you. For all he knew, I freed my hands and escaped by myself, taking his mask and air tank."

"What about the tyre on his car? I cut the valve stem."

Michelle thought for a moment. "I could have used a piece of glass to do that... I guess. Maybe he'll think it was whatever I used to cut my bonds too. It would fit."

"But wouldn't you have taken the car?"

She dismissed that with a wave of her hand. "He had the key. I couldn't have started it. They always control things like that. I'm sure they think I'm dead by now. The airtank would have run out."

Jill asked, "Do they have radios to communicate with? When Kim went in to rescue you we were in communication all the time. It would be useful to know if they can coordinate."

"No, they don't have radios. They just yell."

Jill nodded and looked at me. "That gives us another advantage."

I asked Michelle, "Do you know where the supermarket warehouse is? We could take some of the remaining stocks from it to make sure we have plenty of food for your friends."

"Yes. There are three of them."

Jill shook her head and looked worried. "I don't think we should touch them. Even when we've got your friends safely away — even then I don't think it's a good idea to go anywhere near the area at all. It's too dangerous to fight these people. And we have plenty of food here. We've been storing surplus for decades."

I thought about the numbers. "Twenty three people — twenty six, with us added. That's a lot of people. We'll go through food nearly thirteen times as fast as the two of us alone could. We'll consume in a month what the two of us did in a year. We need to count up how much food we've stockpiled, but I'd guess we have about anough to feed the two of us for maybe two years. With the increased population that's maybe two months, maybe three or even four if we're using as much of the Habitat's resources as possible too. We need warehouse supplies to give us enough time to expand the Habitat."

Jill asked Michelle, "Does your group have more than one car?"

"Yes," she held up three fingers, "three."

Jill looked a bit more relieved. "We could watch car movements from a distance for a while so we knew where each of them was and what their habits were."

Michelle said, "They have a very regular routine they almost never deviate from."

"Good. How many go out to retrieve food from the warehouses?"

"One boss and one worker."

"Is the worker ever out of sight of the boss?"

"Yes, but not for long. The boss usually waits in the car and the worker brings boxes of supplies out to the car."

Jill smiled. "I think I know how we can do this... at least part of it, anyway. We watch and wait for a car to go to a warehouse. When a worker goes inside to get supplies, Michelle meets them and takes them out a different door — most buildings have multiple exits — and wait for the boss to become impatient and leave the car to go inside to find out what's taking so long. We then either take the car or disable it. After a while, a second car will be dispatched to the first to investigate the missing boss and worker. Hopefully, this one will have two bosses in it. I'm sure we can work out a way to disable that car too, without putting us in danger, then we leave immediately for the main living compound. After a while the third car will go to find out what's going on. That's when we go in and liberate the rest of the workers. There will only be perhaps one or two bosses to look out for. Depending on the layout of the compound we might be able to do this without coming into contact with any of them. If we do this properly, the bosses will never see any of us. All their slaves will just mysteriously disappear."

I thought for a little while. "Sounds promising. But what if--"

The microwave oven beeped, so I got up and walked over to the kitchen area, speaking as I went, "What if only one boss is in the second car and the third car each. That would mean there are three bosses still to contend with."

Michelle said, "And don't forget the boss women. They're as dangerous as the men."

I got the bowls out. They were made from a ceramic foam so that they were just warm to touch even though the food in them was piping hot. Using a fork, I held up a small piece of broccoli and blew on it for a few moments, then sampled it. I'd guessed the time pretty well. I set all three bowls on a tray along with cutlery, squeezed some lemon juice over each, then brought them back to the low table in the living area. Setting them down, I motioned for Jill and Michelle to help themselves. "Careful, Michelle. It's very hot."

Jill picked hers up, put it in her lap and frowned, obviously still thinking about the planned rescue. "Maybe we could arrange a distraction to take their attention away from the workers as we're hustling them away. Michelle, after dinner, if you draw some ground plans of the buildings you've been living in we might be able to work out a way to do it. We'll have to research this carefully. We'll only get one shot at it. After that, they'll be more alert and defensive. We can't risk getting hurt. I don't want us to tangle with them. I don't want them to see us doing this... or to see us in the future... ever. We don't want to get revenge on them, or taunt them, or hurt them in any way. We only want to help your friends escape — have them magically vanish."

That sort of ended the conversation for a while, even though it was clearly still on our minds. I suggested we watch a video. They agreed, Michelle emphatically so, as she hadn't seen a movie since she was very young, before the catastrophe. So I played one of my all-time favorite movies: an English-dubbed version of the sweet, Japanese, animated romance, Whisper of the Heart.

After the film, which Michelle thoroughly enjoyed, I washed the bowls and cutlery while Jill fetched clean bedding and night clothes for Michelle, and they made up the bed in the room Jill had helped her choose earlier. It had been a long and eventful day and we both needed to be up early for the chores we'd skipped because of our scavenge run, so Jill and I went to our room.

I was tired, but felt too keyed-up to sleep. "I can't sleep, honey. I feel like I want to keep a record of this... a journal. What happened today is going to change everything."

"Don't stay up too late, sweetie."

We kissed, then I got up, threw on a dressing gown, and went to our small study, and began writing this account that you've read so far. I've never tried to keep a diary or a journal before, so I don't know how well I'll manage this. I simply feel I should. Before, when it seemed like only Jill and I remained, there was no real reason to leave a record. Who would read it? But now that we know other people have survived, it feels important that I try to document things going forward.

One thing I want to mention here is the relationship between Jill and me. Jill doesn't think I should; she says it's like I'm making excuses, but that's not how I see it. Jill and I love each other deeply. We are best friends and lovers. We've been sleeping together, making love to each other, for more than twenty years. We don't think of ourselves specifically as lesbian, but not as straight either... it's difficult to explain. Jill says love just is — no further details needed. I see us as incredibly lucky. How painful life would have been for us if we'd been incompatible.

Ever since the last of the other members of the Habitat died about twenty years ago we had thought we were the only two people alive. We depended entirely upon each other and had found comfort and love in each other's arms against the implacable hostility of the brooding, malevolent world surrounding the oxygen-rich bubble we lived in. Did that define us as gay? Would it have been different if the catastrophe had not occurred? I have no idea and I don't really care. Humanity was wiped away, along with its narrow views on irrelevant things. We're simply ourselves, managing to survive as best we can in a changed world, where each day might be our last. Our mutual love keeping us alive for each other, buoying us up.

I don't know if I'm explaining this properly. What I mean is that I think this is how it should have always been; it is simply a good thing when two people find comfort in each other's arms. They shouldn't be labelled something because of sexuality, or skin color, or handedness. Those things may describe people to some degree, but they don't define love — when two people are lucky enough to have found that bond in each other. And whether it is lifelong (as it seems to be for Jill and me) is beside the point too. What is important is finding that place of warmth, trust, and comfort in each other-- nothing else really compares... or that's how it feels.

It shouldn't need explaining, but if I'm going to write this account properly, it is important to me somehow that the reader should understand this.

Jill reads everything I write, and on reading this, she grinned and said, "So, it's important that it's unimportant?"

Yes. It may sound silly, but I think that's it.

* * *

part 4 - tour

In the morning Jill and I were munching a light breakfast of sweet-potato crisps and talking about ways to expand the Habitat when Michelle shambled sleepily into the living area, yawning and rubbing her eyes. Toby half-heartedly woofed a few times, but didn't get up from under the table. Gina wandered over to greet Michelle, wagging her tail. Michelle smiled sheepishly, "I slept really soundly and couldn't work out where I was for a moment when I woke. And then I remembered. Thank you, both." She patted Gina awkwardly on the head.

Jill beckoned her to the kitchen counter where we were eating and patted a high stool beside her, but after a couple of steps Michelle's eyes were drawn by the outside light and sounds to her left, and she turned to see the Habitat beyond the glass doors lit by the gray morning light. She stood, transfixed for a while. Birds were singing and hopping about the foliage and occasionally darting between boughs. Butterflies fluttered between blooms. Frogs creaked and chirped, grateful for the morning damp.

I stood and walked around the counter into the kitchen area and asked, "What would you like for breakfast, Michelle? What do you normally have?"

She tore her eyes away from the scene beyond the doors. "Uh, workers only have one meal a day: dinner in the evening."

"Well, you're welcome to have more here. We often have something small in the morning. Sometimes we eat a snack in the middle of the day too, if we feel like it. So, would you like some oats with some fresh or dried fruit and goat's milk, or would you like some bread and butter with any of various spreads, or would you like some eggs and some bread, or would you just like some fresh fruit?"

Michelle's eyes lit up. "You have fresh fruit? Oh!" she moaned, "I haven't tasted fresh fruit since I was a young girl. Yes, please." She sat at the counter beside Jill.

I nodded and went to the small fridge. This was for short-term storage only, unlike the cool room. Like the cool room, it was top-opening to conserve energy. I lifted its top and rotated the wheel by hand. The shelves inside rode on a pair belts. They rose in one half and lowered in the other, with the top shelf moving from the rising column to the dropping column, while the bottom one shifted the other way. I circulated the stacks until the fruit shelf was at the top, displaying its contents. "We still have some guavas, gooseberries, and mandarins. We always have apples because we can store them in the cool room. The mangoes should be coming on soon, I think." I looked questioningly at Jill. Her sense of time was much better than mine.

Jill shook her head, "Not yet, I think. Don't forget we still have some coconuts in the cool room from last month's trip to the coast. And the tomato plants are still producing a little." She smiled apologetically to Michelle, "This isn't the best time of the year for fruit."

I raised my eyebrows to Michelle, "So, what would you like?"

She laughed, "I don't know. Wow! A mandarin? Or maybe an apple?"

Jill and I laughed too. It was nice to have someone to show us how special all the foods really were. We'd come to see so much as normal. I got a mandarin out of the fridge and took it over to Michelle. Then I went back through the kitchen area, walking into the back of the larder, past the hatch of the freezer room, and to the hatch of the cool room, which I slid aside with my foot. Descending the stairs I grabbed a few apples from their shelf and went back up to the kitchen. The cool room door automatically slid shut behind me.

Jill was showing Michelle how to peel the mandarin and eat it in segments, their arms over the sink because the fruit was very juicy. Michelle kept making appreciative noises and laughing. When finished they both washed their hands. Jill transferred the mandarin skin to the compost bucket and the seeds to the seed tray for later replanting, then wiped down the sink.

Michelle said, eyes shining, "Well, I never realised how wrong flavored drinks and sweets are. They taste nothing like the real thing."

I handed her an apple. "Have you eaten an apple before? You know not to eat the core, right?" I demonstrated, chomping into mine. After a few bites, I pointed to it and said around a mouthful, "The core with the seeds."

It was fun to watch Michelle munching and slurping on her apple.

Jill beckoned, "We should show you around." She crossed the living area to the glass doors. As soon as she opened them, the morning twitter of many small birds was suddenly loud and clear, no longer muted. Sweet scent rolled invisibly into the room. Michelle appreciatively took a deep breath, closing her eyes and going up on tip-toes. Then they both walked out to the garden, which was mostly in early morning shadow, but softly lit from the east, on our right, by the dull orange, permanently overcast sky. Gina and Toby followed.

I fetched the small trolley. It had a basket sitting on an axle for its two wheels. A long, extensible handle let it be pulled along behind while walking. When stationary it sat upright on its two wheels and a single leg. Into the basket I put two bags which I grabbed from the cool room. They were filled with goodies for the animals. Lastly I added, from the drying rack by the sink, a large glass bottle which I corked, a drinking glass inverted over it, and the funnel, then pulling the trolley along behind me, I followed Jill and Michelle out into the sweet air of the garden, pausing to close the glass door behind me.

Michelle was looking around in awe. We were standing outside the living quarters, but inside the high, transparent dome of the Habitat. Ahead were fruit trees surrounded by grassy areas and shrubs and some small vegetable patches. Everything was wet and glistening with droplets in the dim, diffuse, early morning light. She was breathing deeply through her nose. "What is that beautiful scent?"

I smiled and breathed deeply too, "Lovely, isn't it. It's from all the flowers. The mulching grass gives a nice perfume too. Ummm..." I rubbed my forehead absently, trying to remember the name of the chemical that was the attractive aroma released by hay. "Ah, coumarin."

They both looked at me and I shrugged.

Jill pointed up at the latticework above, "The dome filters out most of the dangerous ultraviolet, making the light safe. You can still get sunburned, but it's like the light from before the catastrophe when Earth still had a protective ozone layer. We have to allow some ultraviolet to keep the moulds and fungi and bacteria down, or they'd take over."

"That's a lot of glass and metal."

I said, "Nope, no metal or glass. Sealing metal and glass is made difficult because they have different rates of expansion and contraction under changes in temperature. This is all plastic. The clear panels are a kind of thermosetting plastic that doesn't degrade under ultraviolet light, and the supporting lattice is carbon-fiber-reinforced polyethylene, making it incredibly strong — much stronger than steel. It means the dome is lighter, was easier to build, and has less stresses. Flexible silicone joins all the interlocking sections together to take up stress too." I pointed out one such section. I glanced at Michelle and realised that, awed as she was by this place, the technology didn't hold the same fascination for her that it does me.

"How big is this place? It looks enormous!"

Jill said, "It doesn't feel so big after you've lived here for decades. The center of the dome is thirty three meters above the ground we're standing on. It's not so high viewed from the outside though, because the ground level in here is roughly five meters lower than the ground level outside," she pointed to the five meter high dark wall at the bottom of the dome beside the living quarters. "It discourages plants, especially vines, from growing up the inside of the dome wall. It also greatly reduces stress from strong winds. From one side to the other is about ninety meters. But this is really only about a third of the structure. It's actually a sphere one hundred meters across, two thirds of it underground. The entire Habitat is made up of seven of these spheres, all linked together via airlocked doors. The seven spheres are laid out like a six-petal flower, with the seventh one in the center, connected to the other six. Each one contains a different environment. This one is Temperate-1. The one in the center is Temperate-2. Another two have savanna climates — Savanna-1 and Savanna-2. The three others are Rainforest, Lake, and Marine."

"Lake and Marine? What's the difference?"

"Marine has salt water. Lake has fresh water. They're the two most difficult environments to manage. Everything in them grows so fast it makes them very unstable. In the early years species would quickly go out of control. We still sometimes have problems with them. The two savanna regions are the easiest to manage. They're used mainly for growing grains. Most of our traditional fruit and vegetables come from the temperate domes. They're pretty easy to maintain too. I wish we had another rainforest. It's really easy to manage and is very productive, though not as insanely fertile as the two water environments, of course. We get a lot of food and other things from the Rainforest. It's where our chickens live, laying eggs for us." Jill grinned. "You can enjoy some eggs in tonight's meal, if you want."

"Real eggs! Wow! I'd like that."

* * *

We strolled down the gravel footpath preceded by Toby and Gina, past the vegetable gardens and fruit trees toward the center of the dome. I followed, towing the trolly behind me. Eyes wide, Michelle looked around her, indicating everything with a sweep of her arm, "So, this is how you get the oxygen we're breathing?"

Jill answered, "Actually, no. Well, it produces a lot of it, but we have hundreds of trays of oxygen-producing algae in the sterile conditions of our laboratories underground where there's no risk of contamination with rogue algae. That's where most of our oxygen comes from. It's easier to control oxygen levels that way, without having to worry about the rates of decomposition of vegetation, or the amount of fish and birds and other animals, or temperature changing how much carbon dioxide dissolves in the water of the Lake and Marine environments. The Habitat's algal systems can compensate for changes, increasing or decreasing oxygen production quickly and easily. The amount of oxygen in the air is picked up by detectors and they automatically vary the intensity of the lights illuminating the algal trays. Electricity for that, and everything else, is supplied by solar cells all around the perimeter of the Habitat and nearby electricity storage. If we were away for days or weeks the Habitat would continue to automatically maintain the balance."

Michelle touched the leaves of a shrub. "Is that dew?"

I chuckled, "No. The sprinkler system is programmed to water everything during the night."

"Is everything automated?"

"Almost. We still have to plant, and weed, and prune, and reap the fruits and veggies, milk the goats, and collect the eggs."

"Where does the water come from? Do you have a well?"

"There is a backup well, but it hasn't been needed in the more than fifty years since the Habitat was first being built. All our water is recycled. Evaporation during the day condenses on the inside of the dome and is caught and channelled into tanks. That's filtered for safety's sake to become our drinking water and is sprayed as rain each night."

We walked around a couple of mulberry trees to reveal the fan — a large, vertical, free-standing panel attached to a pole about as thick as your arm at the center of Temperate-1. The bottom of the structure was about a meter above head-height, and it was another four meters taller. It was made of a lightweight flexible plastic, strengthened by ribs radiating from the narrower side to the wider.

Michelle looked at if for a little while. "What's this? It looks like a sculpture of the tailfin of a giant fish."

Jill laughed in surprise at that description, then pursed her lips in thought, "I'd never thought of it as being like that, but you're right. I'd always thought of it like a bird's wing, though it really owes more to the handheld paper fans people used to wave in their faces to keep cool on hot days."

I explained, "Back when Biosphere 2 was built in USA, they found that some plants do best if they're exposed to some wind. In the early days here, we had a large rotating fan to create a wind, but it had two big drawbacks. It was noisy, and small birds were occasionally killed by the blades. The first thing that was tried was to enclose it in a mesh shroud. That protected the birds, but wasted energy and seemed to make the noise worse. So this was developed. It's silent and doesn't hurt anything. The Habitat's computer starts and stops it at random times and the direction it points is also randomly chosen. There's one of these in each environment, except the Rainforest — there's no room there — and the water environments both have two; one each in the air and in the water."

Michelle said, "You mentioned the laboratories earlier, where the algae are that make the oxygen, that they're underground. Is that like the living quarters?"

Jill said, "A little bit. The living quarters are barely underground, with just a meter or even less earth over them. The ground we're walking on has to be deep to support the trees. In the two temperate environments it is 16 meters deep. In the two savanna environments it's only 8 meters deep. The laboratories are under that."

"What about the two water environments and the rainforest one?"

"The two water ones are water all the way down. There aren't any underground labs in those, but there are some small underwater ones, not much bigger than the living quarters. The rainforest is a special case. Originally it was thought that the trees would require all the root space, so it it was built without much more than a few small underground labs, but our research indicates the trees don't need or use all that volume. Their roots are concentrated near the surface."

I added, "If we were to build it again we would give much more room over to underground lab space in there. And we would add more depth to the ground in the savanna environments. The few trees there, it turns out, do like deep soil. The designers got those wrong."

Jill said, "We'll have to carefully consider exactly this kind of thing now it looks like we'll be taking on more people and building additional environments."

Michelle asked, "Could I see the laboratories?"

"Sure," I said. "We just need to finish our chores first — we skipped them yesterday when we were out. Then we can show you around some more. We need to pick any ripe fruit and vegetables that are ready, milk the goats, and collect the eggs."

Jill grinned. "Picking the fruit is the best part."

We spent the next couple of hours filling the trolley with vegetables and tomatoes and doing a little selective weeding. We took the weeds with us for the goats.

Finally we went to the large door that was the three-part airlock into the Savanna-1 environment.

Jill yelled to Michelle over the noise of the powerful decontamination air jets, "The system of airlocks is designed to make it difficult to accidentally transfer contamination from one environment to another. It hasn't really been needed for a long time, but you can be sure that the day we stop using it will be the exact day it'll be required. And it really isn't much of an inconvenience... except to the dogs. They hate it."

Gina and Toby had their heads bowed, eyes almost closed, and tails between their legs. I patted them in reassurance.

When we were through the final door the dogs bounded joyfully ahead to go meet the goats.

We strolled after. There were only four fully grown goats and our newest addition, Pixie, who we couldn't see yet. We kept our flock small by giving the fenales contraceptives. The goats had noticed our entry and were approaching us. Michelle remarked that there weren't many trees in here and they weren't very tall.

Jill said, "A few pear trees, some almond trees, and in Savanna-2, some olive trees." I pointed to the heavy wire shrouding the trunks of some of the nearer trees. "We have to protect the trunks of the trees from the goats or they'd ringbark them, killing them. They are incredibly destructive. But we don't really grow many trees here — mostly grains. This is fallow at the moment — resting from its previous crop. Around the perimeter there are a lot of fast-growing shrubs for the goats to eat." She pointed out the system of fences around the edge of the habitat that protected the sections of bushes until they could be demolished by the goats.

I took the glass bottle and funnel from the basket and handed them to Jill, then removed one bag and the collected weeds from the basket and latched its lid down so it couldn't be opened by nosey goats.

Pixie, Nubi's latest little kid, had noticed us and came rocketing our way, galloping and bouncing erratically in a wide arc past the other goats. She stopped at Michelle's feet to look at and sniff her, then abruptly raced off again, hopping, skipping and bouncing in that exuberant way baby goats do. Michelle laughed at her antics. I handed Michelle some biscuits from the bag I'd removed from the basket. When little Pixie circled back around again, Michelle squatted down to offer her one, but Pixie had other ideas and jumped on Michelle's back, playing king of the hill. Michelle, giggling, broke off a piece of biscuit and held it up behind her head. The little goat took it and leaped off to go galloping around the other goats again.

The group of older goats were close now and Michelle stood up. I noticed she looked a little intimidated, so reassured her, "Don't worry about them. They're totally friendly." I pulled more biscuits from the bag. "They love these." I showed her how to feed them from the palm of your flat hand.

When Capri, one of the adolescent goats, butted her gently I chuckled at her worried expression and pushed the goat aside. "It's okay. She's just playing. Just remember, you control the biscuit, so you have the upper hand." I lured some of the goats away from her with more biscuits.

Jill led Nubi, the milk-laden doe over to the goat-castle. We followed.

Michelle asked, "The goats live in there? That's gorgeous."

The goat-castle was about three meters diameter at the base. It was basically a tube with a conical cap on top and a walkway that spiralled around the outside, giving the goats access to the four storeys of rooms. I explained, "Goats love to climb on things. We saw a picture of a goat-castle in one of the hard drives from a scavenging trip some years ago and thought it was a great idea, so we built them this. They love it."

Inside the bottom room of the goat-castle, Jill got the bowl down from its hook, put it on the bench under the tap and ran some water into it while she got the cake of soap. She put the bowl under Nubi, carefully washed her hands and Nubi's teats, then put the soap away, and threw the water out the door onto the grass. Now she rinsed out the bowl with more water, then washed the soap off Nubi's teats, threw that water out too, and hung the bowl on the hook again. Now she sat on the small milking stool with the large glass bottle and funnel under Nubi and began milking her. I gave Nubi another large biscuit which she munched contentedly while I rubbed her ears and told her how beautiful she was. She watched Michelle placidly with those weird, horizonally slit, alien eyes that goats have. It surprised me that Nubi and the other three goats accepted Michelle so easily. With a lifespan of only about eighteen years, none of the goats had ever seen any humans other than Jill and me. Perhaps they took their cue from us: we were relaxed about her so they were too. Or, perhaps because nothing had ever harmed them there was nothing to worry about.

It only took Jill a few minutes to finish milking. We didn't take all Nubi's milk, but left plenty for Pixie. Jill got the glass out of the trolley, poured some milk into it and offered it to Michelle who took it reverently and drank it slowly, her eyes closed in pleasure. Jill washed out the empty glass and inverted it over the now-corked bottle, in the trolley basket, then gave Nubi a hug and another couple of biscuits.

We went for a walk around this environment to check the damage the goats had done. Along the way, we explained ot all to Michelle. We'd had to fence off groups of trees and vulnerable shrubs and had planted some fast-growing wattles. The goats loved them, and they're legumes, so they enriched the soil too. The trouble is, the goats never knew when to stop eating, so we had to keep fencing off areas to allow regrowth. It was a bit annoying. I wished they were more like the dogs. When Gina and Toby were full they simply didn't bother to eat for a while. That concept seemed completely foreign to goats. So we fenced areas off and let them stay just a little hungry — not starving, just trim. It seemed to keep them healthier and certainly put less pressure on the environment.

I said to Jill, "If we're getting more people and building more environments maybe we could expand the goat herd."

Jill pursed her lips, "I'm not sure goats would be an efficient use of space until we have a lot more environments. They make it hard to grow anything else. We're going to have to maximise production if the Habitat is to support twenty five people. This is going to be a difficult problem and we need to plan it carefully. I like the goats and I don't want to lose them, but increasing the herd is a luxury we probably can't afford. Another freshwater environment would probably be the most productive way to expand."

I nodded, realising she was right. "Risky though. If it got contaminated it would have the most to lose."

Jill agreed, then said, "I always thought the designers missed out on a great opportunity by not adding an environment that was mostly shallow water plus dry land."

I nodded, "Fish, rice, water chestnuts, water cress... there's probably heaps more that could be grown."

"We could probably find some plants still growing in old farms. I wonder how far we'd have to travel... we'd have to decontaminate them really, really carefully."

We spoke more about the possibilities as we headed over to the airlock that would take us to Temperate-2.

When we were through, both dogs eagerly ran ahead again.

Jill laughed, "They're off to check under the avocado tree for any fallen fruit. They love avos. I think it's ended for the year, though. They'll be lucky to find one."

I beckoned Michelle away to the left of the exit. "Over this way while the dogs are busy." I pointed to a nearby area carpeted in green, with small bits of shiny red peeking out from under the leaves in several places. "You're here just in time for the first strawberries."

Jill joined us as we squatted down. Jill said, "Only take the reddest ones." She picked one and handed it to Michelle. "Here, try that." She grinned in anticipation of Michelle's reaction, and wasn't disappointed.

"Mmmmm." Michelled closed her eyes and slurped the juicy, tangy, sweet fruit. "This is wonderful," she groaned the words. She shook her head slowly in amazement. "Are all the artificial flavorings so very wrong? Strawberry-flavored things taste nothing like this. Well, maybe a vague shadow of similarity... but so, so different."

Jill shrugged, "I don't think we've ever tasted artificial flavors, so couldn't really say. You know, that's something I never understood. I've read about how so much food used to contain artificial flavors and artificial colors and artificial textures. I often wondered why people bought such stuff. If they don't actually contain food, other than maybe sugar, starch, and oil, why did people buy it? I mean if something looks, tastes, and feels like something that it isn't, then it's a lie. What's the point in eating a lie? And worse, a lie that makes you sick. Maybe there was something to it that I could only understand by being in that culture, but it sure seems crazy to me."

I was still poking around lifting strawberry leaves. Eventually I sat back on the damp grass. "Only six. Here..." I offered, and deposited the six strawberries into Michelle's cupped hands. "There'll be more ripe tomorrow."

Jill said, "Looks like a good crop coming on this year."

"If the birds don't get them all," I added. "If they get too greedy we'll protect some of the strawberries with netting."

Jill stood, brushing her hands together, "Let's see what else is on before we get to the Rainforest."

We wandered through the garden, under the fruit and nut trees, until we reached the door to the Rainforest habitat. We told the dogs to stay, leaving them in Temperate-2. As we entered the airlock to the Rainforest environment I explained, "We don't bring the dogs in here because it makes the hens nervous and the rooster tries to pick fights with them. We trust the dogs, but it isn't worth the trouble."

The rainforest was dim and the air was moist and heavy, and echoed with the chirps and calls of birds. I loved the earthy smell in here; it always brought a smile to my lips. And it was definitely a feeling of being inside. The savanna environments felt like they were outside, and so did the temperate ones even though the dome could be clearly seen containing them. It was the external light I guessed. Here you couldn't see the dome, but everything was enclosed in an indoorsy dimness.

The ground was a soft carpet of leaves from the foliage far above. There were hundreds of trees in here, but walking was easy as there was no undergrowth. And the designers had excluded thorny and stinging plants.

I opened the basket, took out the other bag and called out, "Heeere, chook, chook, chook! Heeere, chook, chook, chook! Heeere, chook, chook, chook!"

Jill said to Michelle, "When they come running, look for the rooster and keep your eye on him. The minute you lose track of him he'll know it and attack you. We keep his spurs trimmed, but they still hurt. He's a real bastard." She grinned, "Not his fault. He thinks he's protecting his girls... but he's still a right bastard."

Soon the eight fat hens came hurrying out from the forest to the meagre light here near the edge of the habitat. I cast about us some handfuls of grain and the hens settled to methodically scratching and pecking while the rooster circled, watching us, waiting for an opportunity to catch us by surprise and show us who he thought was the boss. While the birds were busy I handed over the trolley to Jill and she went off into the dimness to search the hens' favorite laying spots for eggs.

I told Michelle of some of the other things we had in here. There was a large pond with water dragons (at her puzzled look I explained they were meter-long lizards), many kinds of small birds, large earthworms about a meter long and as thick as your thumb, a family of crows, a couple of small bat species — one nectar-drinking, the other insectivorous — and only one species of parrots: rosellas. I explained that Australia used to be the land of the parrots, and in doing so I made myself sad thinking of all those beautiful, intelligent creatures gone forever. I would never see budgerigars, cockatoos, galahs, corellas, king parrots, lorikeets, or all the rest, ever again.

I said, "I wish we'd brought some more marsupials into the Habitat, but it wasn't built as a life preserver. It was meant as an experiment, testing life support for people living on other planets."

Michelle asked, "Why did they add the parrots here then?"

"I'm not sure. It was probably to do with balancing the ecology. Almost all these are native trees. I guess there's a long history of people in the Northern Hemisphere living in temperate and savanna environments, but no real equivalent in rainforests. I mean, there are plenty of examples of people living in rainforests, but not in the mainstream literate cultures. I'm not sure who was responsible for designing this Rainforest environment, but it seems like it must have been a work of love. I've certainly grown to adore it in here." I took a threatening step toward the rooster who was attempting to circle around behind us and he backed off. I laughed, "In spite of the damn rooster."

Jill came back with ten eggs, a few Davidson's Plums, and a couple of mangoes. "I was wrong about the mangoes. They've started already."

We threw a few more handfuls of grain to the hens then left.

Back in Temperate-2 the dogs greeted us as if they hadn't seen us for hours. We walked with them to the door for Temperate-1 and went through, bringing us out near the living quarters again. We went inside where I put the bottle of milk in the refrigerator (after giving a little to the dogs), washed the funnel and left it on the drying rack, then finally put all the fruits, vegetables, and eggs away. Jill and Michelle stretched out on the armchairs in the living room munching on apples, and when I was finished I joined them.

Jill said, "We need to work out a good solid plan to rescue Michelle's friends."

Michelle said, "I can draw the layout of the building where everybody lives. The bosses have separate living quarters from the slaves, which will make it easier to get the people out."

I pushed a tablet computer over to Michelle, but the way she looked at it, it was clear she had no idea what it was or how to use it, so I said, "Wait a minute..." got up, and fetched some paper and a pencil from another room and gave it to her.

Michelle started drawing a floor plan of the building where her friends lived, describing what she was drawing as she went.

When it was finished Jill and I asked questions about roads, nearby buildings, where they kept their cars, and so on. Using the tablet computer I tried to use this information to locate the building on a map.

Jill asked Michelle, "Are any of those people likely to cause trouble? Would any prefer to stay there? It wouldn't be a good idea to bring anybody here who could ruin everything. I know you probably think nobody would be crazy enough to want to stay there as a slave, but back when slavery was common the head slaves could sometimes be as dangerous as the bosses, for fear of losing what privileges they had. Are there any like that among your group? One of the great dangers of a rigid hierarchy is that it perpetuates itself even among those enslaved. I don't want us to go to all this trouble and danger, and end up having it go horribly wrong just because someone prefers the devil that they know. It would be awful to simply bring slavery here, with someone deciding they're able to call the shots now that the bosses are gone."

Michelle looked thoughtful.

Jill clarified, "Do any of the slaves lord it over the others and use anger or brute force or threats or blackmail to get what they want? If so, we probably shouldn't rescue them because they will simply try to install themselves as rulers here."

Michelle nodded. "There are a few."

Jill said, "Okay. We save the children and women first, then the least aggressive men. Any man or woman who bullies must not be rescued. Think of it as a disease. We can't afford to infect the Habitat with it." She fixed Michelle with a stern gaze, "Even if you think they're your friend. It's too dangerous."

I had a thought, "Maybe we can use a staging area — a halfway house — so we can see how people respond, without putting the Habitat at immediate risk. I've noticed, when we've been to Noosa in our scavenge trips, there were lots of places that could be easily made airtight." I asked Michelle, "How far did your group range?"

"North to Buderim and Nambour. Mostly we stayed put. The bosses are a bit obsessed with getting down to Brisbane. They managed to reach there a few times, but couldn't stay long. They still sometimes talk about relocating further south. I doubt they ever will though. It's too difficult. And the roads are worse every year."

Jill smiled. "Good. That weights things greatly in our favor. They'll be looking in that direction, not northwest, out here. And it means we're not likely to encounter them in Noosa either. How do you both feel about us making a run to Noosa tomorrow to find a suitable place we can set up with oxygen and food?"

I said that sounded fine to me.

Michelle looked a little doubtful. "Are you saying you would abandon people in Noosa if you thought they weren't suitable?"

Jill shook her head. "No. Not at all. We'll rescue as many people as we can, but if some of those people look like they won't fit in peacefully here, then we'll ensure they have a much better place to live in than they currently have. And there'll be enough supplies in the area for them to live comfortably forever. So they'll have plenty of food and safety, and freedom from those who think they can own them. But we'll give the most gentle people of your group a chance at exactly the same thing: freedom from those who think they can own them. People will be welcome here so long as they don't try to take over. But it's important you don't tell them about the Habitat. Greed can be a powerful motivator for some. It's much better if those who are suitable are pleasantly surprised when they come here. It would avoid disappointments, and prevent aggressive people searching for us."

"Doesn't this mean you'd be doing the same thing as the bosses? Trying to control other people?"

"No, Kim and I have no desire to rule over other people. We welcome people here just so long as they don't want to dominate us and others. But if they do, then they can go somewhere else. We'll even help them do so and ensure their safety elsewhere, but we won't tolerate any kind of aggression. We're tolerant of everything except intolerance." She smiled at the subtle joke and glanced at me.

Jill and I had often spoken of this — not in terms of what we would tolerate — after all, we'd thought everybody was already dead and gone. Our discussions on the topic came out of reading books and watching movies. We'd long ago come to the conclusion that the worst feature of all human history was people's intolerance. Bigoted groups would encroach upon people who were tolerant, and if anybody complained, that objection would be paralysed by cynically calling it out as intolerance. For example, extremist Christians would campaign hatefully against things like gay marriage, women's rights, sex education, other religions, and so on, but if people tried to oppose those efforts the extremists would cry victim. It was an incredibly hypocritical thing to do, but it worked. Extremist muslims did the same thing. So did all kinds of political and economic groups. Very wealthy people would marginalise the poor, making life more and more difficult for them, but when there was any kind of attempt to stop this they would howl that their rights were being infringed upon. It seemed racists were particularly adept at playing that game. They would insist that those who challenged their attempts to sow hate and bigotry were restricting their right to free speech and that they were entitled to their 'opinions'. The confusion it caused among well-meaning folk allowed the extremists to greatly damage social trust and to hurt many people.

We'd come to the conclusion that all this could have been avoided if people had simply disallowed intolerance. It would have been a self-terminating safety guard. It would have sprung into action just long enough to stop people doing bad things, then would've closed itself down, which is the opposite to racism, religion, and crazy political and economic ideals, which were all self-reinforcing; the stronger those beliefs became the more they grew and fueled themselves to crush all opposition and force those beliefs on others. The simple paradox of being intolerant of intolerance meant that it would only rise when required, then shut itself off when its need had passed. It should never go out of control. It was like a thermostat that would turn a heater on when the temperature was out of bounds, then switch off when the temperature was comfortable again.

I said, "We'll need to use the van. It's the only way we could carry twenty-odd people."


Jill said, "A motor home — like a caravan that can be driven, or a bus that is mostly caravan inside. It was in the garage when we drove in yesterday."

"I guess I was so over-awed I didn't notice it. I remember a truck, though."

I nodded. "Unfortunately the truck's back section — what do you call the back of a truck? — it isn't airtight. We'd sometimes considered sealing it, but there was never any pressing need for it, since both of us could ride in the truck's cabin, which is sealed. The van is much better. It's airtight and should carry everybody. It might be a bit crowded, but they should fit well enough."

We talked for a while about the best and safest ways to get the people out of the compound in Caloundra. We'd abandoned our earlier idea of stranding the cars. It would take too long and would involve too much risk of being seen by the bosses. Instead we would go to the main building while a food run took two of their cars away.

It was difficult to plan without us having seen the building or neighboring area. It was apparently not far from the warehouse we'd rescued Michelle from, but we weren't familiar with Caloundra so were making plans with only the aid of old maps and Michelle's patchy knowledge of which roads were usable. Of course, we weren't the ones who'd be actually entering the building to get Michelle's friends. She would. We just had to know the roads out of there. We would be waiting nearby, but out of sight to ferry everyone safely away to Noosa as soon as she came back out with them.

The most worrying aspect for me was that we would be going there when four of the thugs were out in cars and we wouldn't know where they were, however Michelle assured us that their routine never deviated and we would have a safe window of time before they returned from a food run.

Toward the end of the discussions that afternoon Jill said, "I've been thinking about the oxygen concentrators ever since you mentioned them, Michelle. I think somebody in your group must have made modifications to the way they work. What a concentrator does is remove nitrogen. There would still be an imbalance of carbon dioxide in the resulting air. I think they must have modified theirs to remove carbon dioxide. If we can work out how to do that we might be able to not only install some in Noosa, but also adapt them to run in our vehicles to extend our range. It would be great not to have to worry about bottled oxygen running out. We might easily make trips to Gympie and even further afield with them."

I thought that was wonderful news. "Michelle, do you think you can take one of the devices? We might be able to work out how they've done it."

She smiled, "Well, they have six of them. They won't need them all after most of the people are gone. I'll see what I can do."

After going over the various aspects of the plan a few more times we decided to give it a rest for now. It was nearing dinner time. I fed the dogs and gathered together a quick meal for the three of us while Jill checked the drives from yesterday's scavenge for good videos to watch. By the time dinner was cooked she had chosen a science fiction romance-adventure set in a casino city under the surface of the Moon. I thought it sounded pretty lame, but Jill had read the book and wanted to see what the movie was like. I had to admit it was better than I expected, though Michelle was somewhat put off by the couple of lesbian love scenes between the two main characters. Jill enjoyed it though. In fact that might have been part of the reason she wanted us to go to bed early.

* * *

part 5 - liberate

In the morning Jill and I rushed through our chores. Michelle helped a little, where she could. And then we were out in the car headed toward Noosa. We'd opened up half of the back seat so Michelle could sit there. It meant less room for gear in the back of the car, but we'd stowed a lot of it in the trailer. We wouldn't be scavenging much today so space wasn't such an issue. Hopefully we would find a suitable place for the Caloundra group, seal it up, stock it with food and equipment, and be back home before dark. We didn't like to travel at night as the reduced visibility forced us to travel much more slowly. Since we were most limited by the amount of oxygen we could take with us we had to be very careful in our use of time. As it worked out, we accomplished all we'd intended and more.

We found a small, modern, two-storey building of twelve apartments — six per floor — that was easy to make airtight as it had already been built with central air-conditioning, so all windows were already sealed. We ensured the building was relatively airtight, closing off the air-conditioning vents to the outside. It didn't have to be perfectly sealed, the way the Habitat was, because there was no requirement to keep the rogue algae out. And of course since the air pressure wouldn't be different on the inside compared to the outside, loss of oxygen would merely be through slow diffusion, so would be minimal.

Luckily, we didn't need to add solar panels because the roof was already covered in them. We cleaned them — they were covered in grime — and did minimal rewiring so we could install supercapacitor banks. There had been many buildings that might have been suitable, but one of the main reasons we chose this one was because of its proximity to a large, unplundered supermarket that had an enormous warehouse out the back.

Instead of oxygenating the apartment building with algae, as we do at the Habitat, we set up an electrolysis system to split water into oxygen and hydrogen. The hydrogen might have been useful, but after some discussion we figured it was too dangerous, so was vented to outside. Producing oxygen with algae here didn't make sense, because without decontamination systems they would quickly become overgrown with the bad algae. Electrolysis would work until we could get one or more of the modified oxygen concentrators from Caloundra.

The day passed quickly and we headed back home with time to spare. We'd even found some nice treats for ourselves as well. We returned to the Habitat feeling very buoyant about what we'd accomplished and what was ahead. Michelle was excited at the prospect of moving her friends to the very luxurious new quarters in Noosa.

Before dinner we worked on the van for a couple of hours, making sure it was ready for the next day's journey. We checked the electric motor, ensured the supercapacitors would be ready to go, verified that the closet-sized airlock built into its door many years back still sealed correctly, and that the tyres, including the two spares, were full. Brakes, steering, even the windscreen washers — everything checked out.

Michelle wanted to save nineteen of the people so I adapted nineteen masks from our stocks to use small oxygen canisters with simple regulators that would each last about ten minutes. I attached the canisters, each about the size of a fist, to each mask where the hose normally connected, so they looked like old World War One gas-masks.

Early evening was spent carefully going over the plan again. We tried to think of everything that might go wrong and how we might deal with it. Eventually, we tried to relax with a movie and got an early night's sleep.

After breakfast and minimal chores we went down to the garage, got into the van and looked at each other nervously. This was it. We drove the large, almost silent, electric vehicle up and out of the Habitat garage into the dreary overcast morning. We hardly spoke all the way to Caloundra. We didn't even play any music to lighten the tense mood, though Jill did jokingly suggest Ride of the Valkyries.

Negotiating our way around fallen trees was much more difficult in the big motor home than the nimble little car. On the other hand, rough patches of broken up road hardly bothered it. We drove steadily, unhurriedly along the gloomy, forest-shrouded road until we reached the Caloundra warehouse district and the trees started to thin out. Now we took things more slowly, straining to see any movement out there which would mean we would have to rethink our plans.

The safe parking place inside a neighboring empty warehouse was exactly as described, with hidden access from a road on the other side of the block. Michelle suited up with mask, goggles, hat and gloves. We checked our radio link with her, then she gathered up the bundle of nineteen masks and goggles and left the van via the airlock. Jill and I donned our gear too, just in case we were needed. We waited, tensely. Over the radio Michelle gave us a low-voiced commentary until she was inside the compound, at which point she had pulled her gear down off her face so her friends would recognise her and we heard not much more than the odd whispered or mumbled word. After what seemed an extremely long time, but actually only eight minutes, Michelle whispered that she was on her way back. We saw them hurrying across the space between the two buildings, most of them covered in blankets or swaddled in layers of cloth. I noticed Michelle and three others were each lugging heavy, suitcase-sized devices. Four concentrators! Upon reaching the van Michelle helped each person into the airlock two at a time and I helped shuffle them through, into the van. Seventeen people. We lost a lot of oxygen, even with the airlock, though not as much as we would have lost without it, so I made sure everybody kept their goggles and masks on until the last person was inside and we were moving. When I was sure the air was good again I took my mask and goggles off and everybody else did likewise. While Jill drove, Michelle and I went around making sure all the canisters were turned off. They would be needed again in Noosa, moving from the van to the apartment building.

Looking around I saw a lot of toothless smiling faces and a few frowns. Most were dripping wet with sweat from being wrapped in protective cloth in this oppressive heat. There were a few children among them. I handed around bottles of water while Michelle introduced us to everybody. Jill couldn't look away from her driving so she simply called out "Hi."

We appeared to have made a safe getaway. Michelle explained to Jill where the two cars had gone, so we avoided those areas and continued north to Noosa.

Michelle, Jill and I explained to everybody that there was a new place waiting for them where they could relax and live really well without having to worry about bullies. We didn't mention anything about the Habitat. That would be kept quiet until we could be sure who to allow in. Questions came mainly from just a few of them. A middle-aged couple, Vikki and Charlie, asked about the availability of food in Noosa. We explained about the nearby untouched supermarket warehouse, and how its proximity had influenced our choice. A tall, wiry old man who introduced himself as Vincent had many questions about how we'd set up the systems — solar power, water pump, electrolytic oxygen generation, and so on. Charlie asked if we considered ourselves the new bosses. We tried to explain, without talking about the Habitat, that this new place was theirs to live in without bosses. It was a gift. We didn't want anything in return. We lived elsewhere, a long distance away. We would visit, if requested, but we wouldn't interfere. It would be their place, not ours. The only thing we asked was that they don't let things degenerate into bosses and slaves; everybody should be equal and allowed to live their lives as they wished. They were very interested to hear that there were twelve apartments, giving them privacy if they wished it — something they hadn't had in many decades.

We arrived at their new home without problem nearly a couple of hours later. Jill drove down into the apartment building's small underground parking garage and drew up close to the entry doors there.

I put on my goggles and mask and Jill called to everybody to don theirs too. Then I left the van through the small airlock and pushed open the apartment door barely enough to slip in. Inside, I raised my mask and cautiously sniff-tested the air. It was fine, so I gave an "OK" sign to Jill, and she started guiding the passengers through the van's airlock two by two.

Everybody was inside the apartment building, face-gear removed. It was much cooler in here, and I noticed there were a lot more smiles now. Many were positively excited. The general happiness increased as we took them on the tour of the building, explaining everything as we went.

Jill said, "Each apartment has its own electric cooking facilities, running water, bathroom, and small laundry. We've already stocked the janitorial storeroom with the most commonly useful goods that we could think of, which should lessen your need for trips to the warehouse. The building has its own large water tank on top, but that isn't full and will need replenishment, so until then you'll have to be careful with the water."

A tall, muscular, thirty-something year old man with awful scars on his face and arms (he'd introduced himself in the van as Ben) said, "That's not a problem. We're used to water restriction. It'll be strange no longer needing to be super-careful of every drop." He grinned, obviously looking forward to it.

Michelle said, "The tank will be filled after the next big rain. Kim has run pipes from nearby tanks that catch water from roofs and a pump will automatically refill our roof tank."

I added, "The water won't be cold because I've set up a solar heater to make the water hot enough to boil off most of the carbon dioxide dissolved in it. Otherwise the water would be very acidic." With a shock, I suddenly understood why all the adults were toothless. Drinking very acidic water all the time had destroyed their teeth. It would have been like growing up drinking only soft drinks.

We showed them the electrolysis systems we'd rigged up to generate oxygen and how to ensure it was kept topped up with water. The portable air bottles didn't need any explanation. They'd been using similar equipment for years.

Down at the same level as the parking garage was the storeroom I'd mentioned earlier. I suggested they keep this stocked with as much as possible so they wouldn't need to venture out during storms.

Lastly, I led them up to the top floor and pointed out where the supermarket was so they could gather supplies as they needed them. We cautioned them to go easy on the supplies. If they were frugal they could make them last for many decades. Jill said, "We might have a way to extend it beyond that, but that's tentative just yet. For now just be careful with what you have."

One of the women (I didn't catch her name) was suspicious and asked, with narrowed eyes, what we got out of this. I was surprised at the way she asked the question and looked at Jill, who seemed to have been caught off-balance by it too. After a moment I said, "Uh... I can understand you being doubtful, considering what you've come from, but as I said earlier, we don't want anything. We're just trying to help."

Jill said, "This is your place to do with as you please."

Ben, the scarred man who'd said they were used to water rationing, stepped forward and shook hands with Jill and then me. "I dunno what to say. This is like a dream. We're very grateful. If there's ever anything we can do for you, we'd be glad to do it."

I just grinned awkwardly, but Jill frowned and said, "Treat each other well. None of this master-slave nonsense. That's what you can do."

Ben laughed, "Absolutely. But always remember if you ever need a hand with anything, you have a bunch of very grateful friends here."

We stayed for a few hours talking to them, helping them settle in. Ben was probably the most outspoken of them, but I noticed that if someone else wanted to say something he didn't talk over them or dismiss what they said. He was confident without needing to dominate. Perhaps they could be a group of equals. Time would tell.

Eventually, Jill and I said our goodbyes to the happy group and, accompanied by Michelle, we went downstairs to the entry area at the parking garage. Jill and I were getting ready to put our masks on when Michelle said tentatively, "Umm... one of the people I wanted very much to rescue wasn't there today. The bosses had taken him and another with them in the cars. I... I know you've already done more than I could ever expect and I'm beyond grateful, but I..." She looked pained.

"You want to know if we can help save him too," Jill said.

Michelle nodded, uncomfortably. "I know it'll be more dangerous to go back there because they'll be on the alert. And I'll completely understand if you refuse. It won't lessen my gratitude at all."

Jill and I looked at each other. I shrugged and said, "Well, we can at least look at possible strategies. Maybe it will turn out to be impossible to do safely, but we won't know unless we look at all the possibilities, right?"

Michelle smiled, relief lighting up her face. "I know I don't have any right to ask it of you, but... he... uh... I... ummm..."

"Love him?" Jill asked.

She blushed and nodded.

Jill gave her a quick hug and said, "Don't worry. We'll see what we can do. If we give them a week to let their guard down we might have more chance."

Michelle's mood deflated. "A week?" Her voice was feeble and stricken.

Jill pointed out, "They'll have more than enough supplies now they're feeding only a third as many people. They'll be on guard after today. Losing you could be an accident — a hapless woman wandering out to suffocate alone. But losing two thirds of their group would be seen as a deliberate assault upon them. They're already unusually aggressive. Now they'll be alert and watchful. It would be the very worst time to try to help him. Best to wait for them to relax."

Michelle's voice was strained, "I know you're right. What you say makes sense, but a week... I'm really scared for him. He argued for me to be spared, which took a lot of guts. The bosses don't like having their commands questioned. I'm not sure he'll still be alive in a week. You have no idea how brutal these people can be."

I said, "I have some idea. I saw the butchery when I rescued you."

Jill said, "In your friend's favor, the smaller population suddenly makes each member much more valuable. They'd have to be really stupid to kill an able-bodied member of that group."

She looked at us both imploringly, "That's what I'm worried about. They are really stupid and paranoid."

Jill fell into silent thought for a while.

After a few moments I suggested, "What about this: I'll try to get an oxygen concentrator operating in the car. The Caloundra group's movements and routine might have changed now. We won't have to rely on bottles of air if we have a concentrator. It would let us stake out and watch them for a while, perhaps over a few days and let us work out a safe way to rescue him." I glanced at Jill, "One of us would have to stay at home to do the chores; we have responsibilities to the dogs and goats."

Jill looked at me fearfully. She knew I meant that I'd be going out to do this and she'd be staying at home. I squeezed Jill's hand. She growled at me, "Don't let yourself be seen by them. Don't put yourself in any danger. I will be so angry at you if you let yourself get hurt."

I said quietly, "I'll work out a way for us to remain in touch via radio."

Michelle's face showed her gratitude. "Thank you. Both of you. Again. I know I shouldn't have asked when you've already done so much. I just... had to. I wouldn't be able to live with myself if I abandoned David. Can I come back home with you? I could help with preparations and it would save you having to drive out of your way to Noosa to pick me up on the way to Caloundra."

Jill and I looked at each other and Jill nodded.

Michelle ran back upstairs to tell her friends she would be back in a few days with David, then the three of us left.

On the drive home Michelle was bubbling with excitement. Her life had changed completely in just a few days. She had gone from being considered a waste of resources and facing imminent grisly death, to being unexpectedly rescued and then having the chance to live in a paradise. After that, she'd had the opportunity to be the hero and help save seventeen others. And now she would soon be going back to free David, the only person who had loved her; the only one who had spoken out for her. She was very grateful to be able to help him in return and was eagerly looking forward, not only to seeing him again but eventually showing him the Habitat. She described him as warm and gentle, strong yet passive, and very patient; someone who the people in the group relied upon, who acted as a buffer between the bosses and the rest of the group. She was obviously completely smitten with him.

When we arrived home and parked in the underground garage I lugged the oxygen concentrator through the decontamination system. That took quite a while because I had to remove its covers and partially disassemble it to make sure it was completely open to the UV. Once it and I were clean I carried it to my main worklab, then looked through the old storage rooms and found the ones that Jill said had been retrieved from the hospital decades ago. I brought one back to my lab. With the two side by side I set about trying to find out how the modified one worked.

After some hours Jill came to the door of my lab, "Dinner's up. How's the work going? Solve it yet?"

I let out a big sigh and shook my head disgustedly. "I'm stumped. There are differences in the mechanics, but the zeolite that I expected they would use to select a gas — nitrogen in one, and carbon dioxide in the other — looks like it's the same. In both machines it appears to be 13X grade. I thought for sure that would be where they differ. Perhaps it's something to do with the pressure change, but I can't for the life of me see how."

She walked up behind my chair, put her arms around my shoulders and kissed the side of my neck. "Come to dinner. Maybe it'll be clearer after eating."

I turned my head to return the kiss, then stood up and stretched. "I'd like that. I'm not doing much good here anyway."

During dinner Michelle and I started talking about aspects of the intended rescue, but Jill shut that down. "This topic makes me very nervous. If it's alright with you two, I'd like to get a chance to digest my meal, so please, let's change the subject."

I apologised and the three of us talked instead about what cool new things she had found on the flash drives from a few days ago, and debated what video to watch tonight.

After dinner I washed our bowls and excused myself from watching the movie because I'd had some ideas I wanted to follow up in our electronic library. I spent most of the evening reading about pressure swing adsorption devices, which is how the oxygen concentrators work. After that I began to find out what I could about mobile radio that we could use to keep in contact while Michelle and I were in Caloundra and Jill was here at home.

It turned out that we had exactly the equipment we needed. I found it in the stock lists from back in the days when our parents and the other scientists were here. Apparently it had been used in the early years after the disaster, when, without networks, smartphones stopped being telephones and became merely hand-held computers. Jill and I had never needed long-distance radio gear because we'd always been together when outside the Habitat, and we'd accepted our parents' belief that nobody else had survived.

I'd located the radios, fetched them to my lab, and was testing them when Jill appeared at the door again. I looked up, "How was the video?"

She waggled her hand in a gesture that meant 'so-so'. "Got much more to do?"

I shrugged. "It can wait til morning."

Holding hands, we walked to our bedroom, lights automatically on before us and turning off behind us as we went.

Normally Jill and I would get out of bed soon after waking, but that morning we lay there longer, discussing the day ahead. She was very worried about me going near the slavers in Caloundra. I think it worried her mostly that she wasn't going to be there with me. Neither of us had gone any great distance away from the Habitat alone, nor spent much time alone inside the Habitat. We went everywhere together. And we'd both had nightmares about being alone in the Habitat, having lost the other due to an accident. I was worried too, though it wasn't so bad for me because Jill would be safe in the Habitat, so I didn't have to worry about her, and Michelle accompanying me gave some safety in numbers. I think Jill was terrified of being alone if something happened to me out there. The fear of isolation must have been awful for her, though she tried to cover it up. I joked that if anything happened to me, at least she now had some ready replacements in Noosa, but she frowned at me and didn't answer.

I took her hand and kissed it, "Don't worry. We'll talk as much as you want over the radio. It will be almost as if I'm here. And I won't be gone more than a couple of days. With luck it may be less. There's no way I'll allow a rescue of Michelle's boyfriend unless I'm convinced it's safe. We just need to observe for a while to make sure. I'll be very, very careful."

Jill still looked unhappy, but nodded.

When we entered the living area Michelle looked up from her breakfast and smiled. "Sleepyheads."

Jill's face was grim, "Actually, we were talking about your trip today, you and Kim."

Michelle's smile faltered, "Is it still on?"

Jill ignored the question, "I'm relying on you to look after Kim. Don't let her take any chances."

I laughed, "Because I'm such a big risk-taker."

Michelle nodded soberly, "You can rely on me, Jill. I'll make sure Kim stays safe. I'm extremely grateful to you both; I'll be very careful to avoid endangering anybody."

Jill nodded, her face a mask. "I'll go do the chores."

Jill never missed breakfast. I was suddenly concerned and went to put my hand on her shoulder, "What about your breakfast?"

She stepped away, eyes on the floor, avoiding me. "I feel too nervous to eat." Then walked out to the garden.

Watching her leave, I felt like I should say something, but I couldn't think of anything that would help. I stared helplessly after her for a while.

Eventually I turned to the kitchen to get my breakfast. Like Jill, I never miss breakfast either, but for different reasons than her. Eating is not particularly enjoyable for me, but because I'm thin I don't have much fat reserve and I don't like running low on energy in the afternoon.

When I sat at the counter with my bowl Michelle asked, "What you said to Jill earlier... do you really take risks?"

"No. I was just joking — trying to make light of her worries. I'm really a very cautious person."

She raised her eyebrows and said uncertainly, "Saving me was pretty risky."

"Well... yes... but that was unusual. It didn't look like there was any alternative and time was important. Most us who built the Habitat and lived here — scientists, engineers, Jill's parents, and my parents — almost all died from accidents, so I'm normally extremely careful. I weigh up all the options and put off acting until all angles are thoroughly examined. Unfortunately, sometimes there just isn't enough time and you have to go with what you have or miss the opportunity."

She looked down at her hands for a moment then back at me. "Well, all I can say is I'm thankful that you did."

I shrugged. "She's angry at me because there are hundreds of simple mistakes that I can make when we go out there and almost all mean death. She's already lost everyone else. The idea of losing me too terrifies her." I thought about it for a moment. "And I can understand that. If it was her going out there instead, I'd be terrified. The idea of being alone..."

"Except you aren't alone now. You have a lot more company in Noosa and another still in Caloundra." She smiled hopefully.

I nodded. I couldn't really explain why that wasn't the same. Jill and I had depended entirely on each other for decades. During that time we'd felt we were the only people left in the world. The effect it had on us was too difficult to describe so I didn't bother.

It didn't take long to get the radios working properly — the benefits of sleep. After that, I spent about an hour packing supplies and tools. I packed sufficient electrical storage and solar panels to ensure we could manage a few days. In addition to the binoculars, so I could watch from a distance, I also added a telescope and small webcam wired to a tiny computer (a Raspberry Pi) which has wifi. Food was easy, but water was heavier and more bulky. I didn't want to use the sharply acidic water from outside the habitat. Then I spent another hour going over, checking and rechecking everything. As the time approached I was surprised to find I was very reluctant to leave.

Jill came down to the garage. I stopped my third recheck and watched her as she walked over to me. I took her hands in mine, but couldn't think of anything to say. Lame as usual, I smiled and said, "You shouldn't have come down here. Now you'll have to go through decontamination to go back inside."

Her voice was quiet, subdued. "Be careful out there. Don't take any chances. Come back safely."

"Of course." I gave her a hug, "I'll be back before you know it." Then I showed her how to use the radio. It was the same as the one upstairs in my lab. She absorbed the information wordlessly then walked away, pausing briefly at the door of the decontamination room to look back at me, then left.

* * *

part 6 - black

The journey was uncomfortably hot, but uneventful for most of the way. The greatest worry was that the eternally overcast sky was much darker than usual. The clouds were so heavy that it was like twilight, even though it was around the middle of the day. I hoped we weren't in for a storm. That could make the whole rescue operation even more difficult. It would reduce visibility badly and hamper our ability to move around outside the car. Also, the carbon dioxide dissolved in the rain made it acidic like vinegar, which meant that removing goggles had to be done carefully, first towel-drying face and hair, lest some water trickle down into the eyes. A painful experience. I half considered turning around and going back — postponing for a day.

Jill spoke with me on the radio several times along the way. The first time she called was to apologise for her moodiness. I tried to make light of it and reassure her. The other times I think she called just to hear my voice and to know I was still here.

Driving carefully along in the deepening gloom under the thick, ominous sky, I was regretting how easily I consented to help Michelle rescue her boyfriend. It's easy to say we can drive down there, and it doesn't look like a terrible distance on a map, but the broken and damaged roads made travel slow, and the unexpected gloom of the stormclouds slowed it even further, so that what might have once been just a couple of hours consumed most of the day.

It had been decades since I'd spent a meal or a night without Jill and I was missing her and not relishing spending the night virtually defenceless in an area prowled by cannibals. I didn't say any of this aloud, not wanting to worry either Jill or Michelle.

As we approached Caloundra the storm broke and sheets of heavy rain crashed down on us, and the almost dark, late afternoon began to flash and thunder. The cool of the rain was a great relief after the oppressive heat of the day. Inching along in nearly impenetrable rain I found an old, small petrol station for internal combustion vehicles. There was some shelter from the rain in parking under its awning beside its ancient, useless refilling pumps.

Michelle wanted to get out of the car to explore and relieve her bladder. We donned our breathing masks and she ducked out the door as quickly as possible to conserve the oxygenated air. There was no need to protect from the sun — at only four in the afternoon the heavy storm clouds had made it as dark as night — but Michelle wore goggles to protect her eyes from the acidic rain and a hooded raincoat to prevent any water getting into her hair or clothes.

While Michelle was gone I removed my breathing mask and tried the radio again, but the constant bangs, pops, and crackles from lighting made it impossible for us to hear each other, so I sat back and looked out into the darkness through the car's windscreen. The roar of the rain on the awning above and the broken concrete outside the protected area was strangely almost comforting. It lulled me into a meditative state where my eyes drooped closed approaching sleep — thoughts, images and half-remembered things surfacing then slipping away, barely glimpsed.

I was startled awake by Michelle rapping on the window and shining her torch on her own face. When I had my mask on she hastily slipped inside the car, slamming the door behind her. We removed our masks again, she carefully mopping her face with the handtowel first. The air stung a little with the extra carbon dioxide, but was bearable. She explained that the interior of the shop had been completely ransacked, though she had found a few candies, which she showed on outstretched hand. However a large workshop was beside the office and she'd raised the door so we could drive the car inside.

When I'd turned the car around as she directed and driven it inside, we both put on our masks and jumped out of the car to pull down the garage door. It unrolled from above, but was incredibly difficult to move. "How ever did you raise this?" I shouted through the mask. Her muffled reply was that it had been much easier to raise.

When the door was down I scouted around the dark interior of the workshop with my torch, finding some valuable tools, which I put in a pile near the car to be sorted through later.

The workshop gave far better shelter from the storm and we felt less exposed using torches and the car's interior light in here, even though we knew it was very unlikely the slavers would be out in this rain. Outside, using a light made us instantly visible in the dark — a beacon advertising our presence. We were much safer in here. And the rain wasn't as loud. Even the thunder didn't seem as earthshaking. We relaxed in the car, and talked for a couple of hours.

I was surprised to learn that Michelle was religious. I'd never met a religious person before; none of the scientists and engineers who built the Habitat had believed in any gods or other superstitions. Jill and I had read plenty of books written by and featuring religious people, and we'd seen plenty of movies and TV shows from DVDs and people's hard drives recovered from scavenging hunts. We were aware of the peculiar dangers religious people present. They can be good and moral people who mean well, but religion can make them do bad things. My mother had been fond of quoting Nobel Prize winning physicist Steven Weinberg: "Religion — with or without it you would have good people doing good things and evil people doing evil things. But for good people to do evil things, that takes religion." Another of her favorite quotes was by Voltaire, "Those who can make you believe absurdities, can make you commit atrocities."

Michelle hinted that David was considerably more religious than she was. I'm aware that historically, it has been very common for religious people take great offense at people questioning their irrational beliefs. Jill often said I lack subtlety, so I was careful not to enlarge on the topic, but to steer around it. I didn't want to alienate Michelle, so we talked mostly about her childhood before the algae changed everything.

Eventually, the storm either exhausted itself or moved on.

Turning the radio on still produced some pops and crackles, though not as loud as before, so I called Jill. She answered, relieved, and we chatted in an aimless fashion into the evening. I don't even remember what we discussed. It was mostly to reassure ourselves and each other, I think. When it got late we closed the connection. Michelle and I reclined our seats and surrendered to sleep.

In the morning the interior of the workshop was dimly lit. Small windows high on the north wall diffusely illuminated the upper part of the West wall.

Michelle and I had a quick breakfast of sandwiches, fruit, and water while I spoke to Jill over the radio. After our morning toiletries we raised the door of the workshop (Michelle was right, it was much, much easier to lift).

The morning was hot already under the gray sky. Great veils of mist obscured much of the landscape. Much of the rain from last night was rising, returning to the clouds.

We resumed driving warily toward the slavers' home base. Rather than drive too close, Michelle knew of a building nearly a kilometer from their place, the top of which, she was sure would give a clear view, letting us watch all comings and goings. When we reached the place, I parked the car inside and walked up the three flights of stairs to the top. There I set up the tiny, high resolution, video camera on the telescope and put the small, waterproofed Raspberry Pi computer under it. We could watch the slavers' place while parked under cover below without risking exposure at all. I used a solar panel maintaining the charge on a small super capacitor to power the Raspberry Pi, and its WiFi link to the car's computer to display the view through the telescope on the car's dashboard screen. I'd also deployed more solar panels on the ground outside the building to recharge the car. We sat back, watched the screen, and prepared for a long, boring wait. At least it would be in the relatively cool comfort of the car instead of up on the roof of the building in the sweltering heat and humidity under layers of protective clothing.

Time dragged. Jill called on the radio when she had time between tending to things in the Habitat. Michelle and I talked a little, mostly about what we remembered of time before the change. Sometimes one of us would doze or read while the other took turns watching the view of the slavers' place on the screen. But there was no activity to be seen. Their two cars simply sat, unused, and nobody set foot outside their building.

So passed that day. It was pretty boring, and the car seats, normally very comfortable, were starting to feel restrictive. We had to get out to stretch and walk around, one at a time, of course; someone always had to stay watching the screen.

By the time night fell I wondered if something had gone wrong there, but Michelle said that it was normal for them to stay inside for many days at a time.

"Many days?" I asked.

She shrugged. "They should need to go out soon. Food stocks were pretty low before. There's less people now, but the nine bosses always consumed most of it anyway."

I said, "Maybe they went scavenging and stocked up while we were getting the building ready in Noosa."

She shook her head and smiled, "No. I was talking to some of my friends when we were putting them in Noosa. They were saying some of the bosses took the cars out searching for me, but came back empty handed. They didn't go to get food. Well, they went to get me — they thought of me as food — but you know what I mean. They see meat as too valuable to lose."

I winced. Hell! How did they get to where they thought of another thinking, feeling human being as mere food? It also brought home to me just how nightmarish these people were. If caught, we wouldn't be enslaved; we'd probably be eaten. For the first time I got a strong sense of the danger I'd put myself in. My optimism tends to give me a feeling of invulnerability. Of course, I am careful and try not to take unnecessary risks, but those risks generally don't feel immediate. I don't get overwhelmed by them. But now I got a peek behind the cutain at something deeply disturbing and I suddenly felt very reluctant to go anywhere near those people. I had a strong urge to give up right then and head back to Jill and the safety of the Habitat.

But I didn't say anything. I'd committed to at least seeing if it was possible to save Michelle's boyfriend. And we'd come this far.

We had our evening meal, talked with Jill on the radio, and eventually went to sleep.

The third day was different. Shortly after breakfast I was reading a book while Michelle was watching the car's computer screen and she suddenly straightened. "Kim!" I switched off my book and looked at the car's screen. Michelle excitedly pointed to one of two figures getting into one of the cars. "That's David!"

I put on my mask and goggles, motioning for her to do the same, then I jumped out of the car, unplugged the recharging lead to the solar panels, and jumped back in. I quickly drove out into the hot, perpetually overcast day and paused. On the screen, their car was heading off south, toward us. Michelle said, "They're going to the south supermarket warehouse!"

We'd already discussed the best routes to various places of interest so I headed off in that direction as fast as the broken road would allow, intending to approach from the other side of the building. The screen image flickered and was gone. Michelle yelped in dismay, but I told her it was okay, that we were simply beyond the range of the WiFi.

She helped navigate to the warehouse so we arrived before them and waited unobtrusively among shrubs that had broken through the tarmac and camouflaged by several ancient, parked cars whose paint had dulled and faded from decades of intense ultraviolet light. We didn't have long to wait. They drove in through the usual entry Michelle had said they always used and parked close to the front door. One of the men got out of their car.

"That's David!" Michelle's whispered voice was tense. She pulled on her mask and goggles.

We'd already checked earlier, but I said "Testing..." into my mask's microphone and heard in my earphone her answer that it was working.

Our position let her carefully exit the car and, bent low, run to a rear door of the building, completely out of view of the remaining man in the car. And I kept watch on him in case he decided to go inside too. If he did, I'd warn Michelle through our radio link. I sat, and watched, and waited.

After what seemed much, much longer than six minutes, Michelle came out the back door with David, heavily clothed, and staying low like her. They ran back to me, then both carefully got into the back seat of the car. We waited for a little while for the oxygen level in the car to come up again, our attention fixed on the other car and the man in it. Michelle, impatiently, was the first to lift her mask and sniff the air. It was okay so she removed hers and pulled David's off and embraced and kissed him. Meanwhile I removed mine and kept watching the man in the other car.

Michelle, after a long embrace and muttering happy coos to David, sat back and said, "Kim, this is David. David, meet Kim."

He was sitting behind me, so I turned in my seat to greet him, but the smile fell from my face when I saw the look of distaste on his and he said, "You're black!"

Michelle looked confused. "She saved both our lives, David." Her voice had a note of pleading.

I was lost for words and turned back to keep watching the other car.

David corrected Michelle, "God saved us."

That pissed me off a bit. Without turning around again, I said, "Really? You don't think that's just a bit arrogant? You think your god murders all the innocent children and every other animal on the planet, but has some twisted plan to send a brown-skinned atheist to save you?"

He said, "We can't know the mind of God."

"Interesting. You knew a minute ago. Don't you think it's a little too convenient that you don't know god's intentions when bad things happen, but you do for good things?"

Michelle pleaded, "Kim, David, please stop. We're not enemies."

The man in the other car must have been getting impatient. He got out to walk into the warehouse. I said, "The other man — he's going to check on you. Time to go." When he was out of sight I gave him a few more seconds to enter the building so he would be unlikely to hear our tyres (he wouldn't hear our nearly silent electric motor of course), then I quickly turned our car and sped back the way we'd come.

We drove in silence for a while. I felt like I should apologise, except I didn't see that I'd done anything wrong. I didn't like Michelle being unhappy, but her precious David was emphatically not a nice person.

When we got back to the building where we'd left the telescope and solar panels, I drove inside and parked. When I got out of the car I made sure took the key fob (the small remote lock for the car) and kept David in view, which was difficult with my mask on, but I didn't trust him at all. After folding up the solar panels and rolling up the leads, I went up to the roof and detached the camera and computer from the telescope, and the telescope from from its tripod, then took them, the solar panel, and its lead back down the three flights of stairs to the car and packed them away. David and Michelle were over near the entrance to the building, masks on, hugging. I got in the car and turned on the radio. After only a short time I removed the mask to call Jill. In my haste I hadn't waited for enough oxygen to build up and I was gasping a bit. Thankfully Jill had been near the radio and answered. I told her quietly, "I'm not bringing Michelle and David home, I'm taking them to Noosa instead because I don't trust him. He's racist, and religious — a very dangerous combination." I noticed in the mirror that they were returning. "They're coming back to the car now. I'll talk to you shortly, sweetie."

I put my mask and goggles back on for them to re-enter the car. When they were safely inside I drove back out of the building and headed north, but stayed very clear of the slavers' area.

There was a very long, awkward silence. Nobody said anything for perhaps quarter of an hour. Eventually I said to Michelle, glancing at her in the mirror, "I'm taking you both to Noosa and leaving the radio with you so we can keep in touch. If anybody needs anything we'll do everything we can to help."

Michelle looked sad. She nodded. She knew why I was taking them to Noosa instead of the Habitat. Some of of my regret must have shown in my eyes. Looking at me in the mirror, she gave me a feeble, sad smile which I interpreted as her understanding.

Most of the drive to Noosa was spent in silence. Michelle made a number of attempts to start up conversation, but they dwindled away to nothing each time. David had no intention of including me — an atheist! and dark-skinned! — in any conversation, and I could hardly wait to unload him at Noosa.

I was sorry for Michelle. She'd looked surprised that he was racist. But then, how would she be expected to know? All the people saved from the slavers were white. If all the rest were white too (a reasonable assumption based upon David's reaction) then she could easily be completely unaware of it. It's probably not the kind of thing that would come up in ordinary conversation.

I'd seen plenty of movies and read many books which portrayed the evil stupidity of racism, but I'd never seen it in actual people before. Growing up among scientists and engineers who'd come from all over the world, my childhood had been a charmed one. My parents were valued members of the scientific community and we had never been treated as different because of our skin. To even imagine such a thing seemed so unutterably ridiculous that it never even occurred to me that it could be something I might encounter. To see it in a real person was shocking. And shackled by a fervently religious mind, I could see that it was unlikely to ever change.

I'm sure David was a good person so long as his prejudices were never challenged, but I doubted he would ever fit in at the Habitat, where those prejudices would constantly chafe against reality. I can only imagine what his response might be when he found that I was also in a loving relationship with another woman. Adding that to my crimes of being atheist and not white, it wasn't difficult to imagine him convincing himself that his god intended him to wrest control of the Habitat from the godless sinners. No. He definitely should not come to the Habitat.

* * *

part 7 - Blossom

I was very relieved to finally reach Noosa. I drove down into the parking garage under the small apartment block and drew up close to the doors. We donned our masks and goggles and Michelle and David left first, then, after unplugging the radio and bringing it with me, I followed. The keyfob was still in my pocket so I pressed it again to lock the car before I entered the building. No sense in taking chances.

Everybody came to greet us. Several were especially happy to see Michelle and David again.

I could distantly hear a young child crying almost as soon as I entered. A distraught woman shorter than the others there grabbed my arm and asked me to come see her baby boy. He was sick. A middle-aged man came with us. Hurrying up the stairs, with us he jogged my memory that he'd introduced himself before as Charlie. He explained that he had a little medical knowledge, that everybody had contracted a mild case of diarrhoea, almost certainly from the water. They now boiled the water before consuming it, and ate some charcoal which he knew took up poisons onto its surface to be expelled. While this seemed to have fixed the problem for everybody else, it didn't help the baby who was still stricken with diarrhoea. They were unable to convince the infant to swallow the charcoal. The sterile water was having some effect on the child, but the worry was that it wasn't working quickly enough. Without books to refer to he didn't know what to do.

The woman dragged me to the room where the child was. He was about two years old and had sunken eyes, which I knew indicated dehydration. A young girl who was maybe ten years old was hovering worriedly over him. I connected the radio to the room's twelve volt electrics, and called Jill. When she answered I told her of the problem.

She said, "Ah. Rehydration solution. I read about it some time ago. It helps the child absorb water and electrolytes. You need sterile water, some sugar, and some salt — we stocked the big supply room under the stairs with sugar and salt. I think the proportions might be important. You'll need a container to measure the water, and a teaspoon for the sugar and salt. Give me a few minutes while I look it up."

The woman said she'd get them, and hurried away.

She returned with them shortly.

A few moments after that, from the radio, "Are you there?"

"Yes. We have water, salt, and sugar, a teaspoon, and a measuring jug," I answered.

Jill asked, "Has the water been boiled?"

The woman nodded so I said, "Yes."

"Okay then, measure one litre of water..."

The woman looked puzzled and the young girl pointed to the litre mark on the side of the measuring jug, so the woman poured water to that level.

I said, "Done..."

"Now add half a teaspoon of salt..."

When this was done, I said, "Okay..."

"Lastly six level teaspoons of sugar and stir until dissolved. This should help rehydrate the child. He'll need his potassium levels restored soon too, but plenty of other foods will help there. I found a short list of foods high in potassium. Hang on... here it is. In descending order, avocado, spinach, sweet potato, coconut water, yoghurt, white beans (I don't know how they're different from normal beans), and banana."

Looking at the distressed woman, I said, "I don't think we have any of those here." She shook her head. "But we have some of them at home, would you like to bring him there to help him recover?"

She looked relieved, "That'd be great if I could, thank you."

Jill said, "I'll get the apartment in the garage ready for you. A sick child might not go through decontamination easily. We can spend some time trying to get rid of the bug that's making your kid sick."

I nodded. "Okay seeya soon. Thanks Jill."

The woman hastily added, "Yes, thank you, heaps."

Jill said, "No problem. Bye."

I left the radio on standby and turned to the woman. "Give your kid a drink of that, then clean him up and wrap him in a towel. Bring the rest of the drink with us. We'll leave as soon as I've shown the others how to use the radio."

I disconnected the radio and took it out into one of the large common rooms, then assembled all those who were interested and showed them how to use the radio. I repeated it a few times to make sure, even though it was quite simple, then I left.

When I met the woman below, in the exit to the garage, her little boy was no longer crying. She'd already put masks and goggles on the child and herself and the young girl who was also there. The woman pulled her own mask down to ask, "Can Kayla come too?"

I nodded and smiled to reassure them, put on my mask and goggles, then pressed the key fob in my pocket to unlock the car. We went through the glass doors into the parking garage and got into the car's front seats, she with her little boy on her lap, and Kayla in the back seat.

After a few minutes of driving we were able to remove our masks and goggles.

She said, "My name is Blossom." She smiled and shrugged, "Hippy parents."

"Ah, yes. I remember the name from the introductions a couple of days ago, though I promptly forgot most of the names and couldn't have connected you to your name, sorry."

She caressed her child's face. "His name is Gabriel."

I thought, uh-oh, another religious person. I asked tentatively, "Ummm... after the angel Gabriel?"

She laughed. "Hell, no. I just like the name. Well... I'd hoped it'd protect us from the others, but it doesn't really. Some of 'em think he's sick because it's their god's punishment on me for not believing. How creepy is that?"

"That's a relief. I thought for a moment..."

"That I was like David? No. He's the most religious of 'em all. More than a few screws loose, in my opinion. How can people seriously believe a loving god kills almost everybody and let a nasty bunch of shits survive to make us slaves, and feed on us." She rolled her eyes.

"How did you know I wasn't religious?"

Blossom grinned. "It was pretty obvious by your look when I said Gabriel's name. That's why I laughed. I know you tried not to show it, but you're pretty easy to read, sorry."

Her child stirred. She uncorked the water bottle, lifted it to his lips and whispered tenderly, "Drink, darling, drink." He sipped a small amount, made a half-hearted whine, and went back to sleep.

After a few minutes I asked, "How many of them are religious?"

"Only a few total nuts. Four, I guess. The rest... well, about half are easy to lead--"

"Like Michelle," I put in.

"Yes, like Michelle. The rest aren't religious."


"A few think it's a stupid question and don't care if there's a god or not. And that's fair enough, I s'pose. Not me, but. It's obvious to me there's not. The rest are like me."

Blossom was earthy, but smart and easy to chat with. She explained that Kayla had become like a daughter and she was extremely close to Gabriel. Blossom had been born after the catastrophe. She'd never known a world of oxygen and blue skies, with billions of people, birds, dogs, horses, ants, butterflies, and all the flowering plants, other than through pictures in books. I was amazed. I couldn't imagine how that must feel. She told me of her childhood and her life up to now. Considering the awful things she'd been through, I'll never understand how she was so buoyant and optimistic about everything — even with her child dangerously ill.

It was easier for me to tell her about my past after the practice of telling Michelle. And when I told her about the Habitat her eyes almost glowed with intensity as I explained that we still had animals, fruits, vegetables, flowering plants and bees, uncontaminated water and fish. I told her about the origin of the Habitat; how it had been an experiment to learn how to build sustainable environments in spaceships and on other planets. I said, "But we'll never see other planets now to fulfil the experiment."

She said, "Yeah, you have. Earth changed into another planet. Your Habitat sounds like it works good."

"Huh. I never thought of it like that."

We talked all the way back to the Habitat. Kayla remained silent the entire way. I actually forgot she was there.

Eventually we arrived home. When we drove around the last bend and the large domes came into view ringed by the solar panels around the base, she whispered, "Wow. It's much bigger than I imagined."

I chuckled, "Then you're in for another surprise, because it's way bigger than it looks."

When the car approached it, the exterior door slid open letting us drive down the entry tunnel which curved gently to the right as it descended. The door closed behind us and we continued slowly down and through the bottom door to enter the large, well-lit underground garage.

Blossom was about to put her mask on, but I shook my head and said, "No need. The air's good in here."

As we were getting out of the car, Jill came striding over to us. She was holding up a baby bottle with a drinking teat. "This is a version of rehydration solution that also contains some of the other electrolytes your child has lost."

She handed the bottle to Blossom, who accepted it gratefully and settled back down onto the car seat again, coaxing the child on her lap to drink some. He drank more this time.

Jill was surprised to meet Kayla, who avoided eye contact and barely reacted to Jill's friendly greeting. Kayla seemed painfully shy. All this time I hadn't heard a sound from her. I wondered if she might be mute.

Jill said, "Your boy will probably be too fragile to go through decontamination, so until he's well enough I've made up a bed down here for you. I can make up another bed for Kayla, if you wish.

Blossom said, "That's okay, she's slept with us since she was little. Thank you both, for this. I'm really really grateful."

Jill said, "Maybe tomorrow, maybe the day after, when he's feeling stronger, you can bring him through decontamination into the main part of the Habitat."

I explained, "It stops the algae getting into the Habitat and contaminating our water. We have to go through decontamination whenever we enter the Habitat, to protect it. It might be a bit rough on Gabriel while he's sick."

Jill beckoned, "The living quarters down here are for when one of us--"

I smiled, "Usually me."

"--needs to work on something over some days."

I added, "It gets a bit annoying having to go through decontamination a few times a day over a number of days."

Our voices and our footsteps on the concrete floor echoed in the cavernous garage as the four of us walked to a door next to the decontamination rooms' double doors.

Jill opened the door and entered. "It has all the comforts and is completely self-contained." Blossom, Kayla, and I followed.

I tapped Blossom's shoulder and indicated a small box on the wall beside the door. "This is an intercom. Press this red button and it makes a buzz in the one in the rooms above to get our attention." I pressed it to demonstrate, and it buzzed. "If we're nearby we'll talk to you through it. This other button lets your voice be heard in the other intercom. You press it and talk while holding the button down. It can show video... uh, don't worry about that, though."

Jill beckoned us into the main area of the living room and walked over to the main wall. A clockface was on the wall above a large screen at a desk. She indicated the screen, "This is a computer screen. It'll also show you information on almost anything you want to know, and play movies, music, talks, documentaries, all sorts of things." I noticed Kayla's eyes were following all this intently.

Blossom had sat on the couch and settled her child on her lap, his head cradled by her arm, and Kayla beside her. She said, "I don't know what most of those things are... I mean, I've heard of some of them, but..."

Jill waved a hand dismissively, "Don't worry. They're not important. You'll get the hang of it quickly enough. The most important thing is to relax and for your boy to get better."

I walked further into the apartment and down the short hall at the back, indicating doors one after another, "Kitchen, bathroom, laundry, toilet, linen closet, bedroom." Kayla's dark eyes followed everything I indicated.

Jill said, "The kitchen is always well stocked with food, and I added some fresh fruit, eggs, milk, and bread for you." Kayla's eyes flicked to her.

I said, "We'll stay for as long as you want and show you how to use everything."

Jill shook her head, "Kim can stay, but I have to get back to feed the dogs soon."

Blossom looked a little lost, "Wow. Kim said you had dogs. I've only seen pictures in books." She shook her head and looked down to her little boy. We've gone from being slaves, to free in an amazing new place, and then here... the world got so big suddenly." She smiled, looking tired.

I said, "You look like you need some rest. What if we leave you be? Eat and drink whatever you want from the kitchen. Wash in the bathroom if you wish. Call on the intercom when you want us. We have to go through decontamination so it'll take a while before we get upstairs... about quarter of an hour."

Blossom looked blank.

Jill pointed at the clock on the wall, "Can you read a clock?" When Blossom shook her head, Jill said, "The long, black hand moves fully around the clock in one hour, so half an hour is halfway around the clock; quarter is quarter of the way. Ignore the short hand and the fast red one. So when the long black hand gets to here--" she pointed to 10 on the clockface, "we should be upstairs. You can call us on the intercom," she pointed at the intercom by the entry door, "anytime after that."

Blossom nodded uncertainly. Kayla gave no indication of understanding. She just watched everything.

As we were leaving I turned at the door, "Remember, press the red button to get our attention with the buzzer," I pressed it to demonstrate again, "then when we've answered, hold down the other button while you speak."

We went through decontamination, returned upstairs, and settled together into one end of the lounge in the living room. I said, "Blossom's interesting. Apparently some of the people in the main group give her a bit of a hard time because she doesn't believe in a god."

Jill frowned, "Yeah, about that, what was the deal with Michelle's boyfriend...?"


"Yeah, David. Tell me more about what happened there."

I took a deep breath and explained how he'd shocked me with his racism, and then his insane religious conviction that we hadn't saved him, his god had. A bit embarrassed, I told her how I'd been unable to hold my tongue and what I'd said in pointed retort to him. I felt a bit shaky again just remembering it. Jill saw how uncomfortable it made me. She put her arms around me and murmured in my ear, "Don't let it bother you sweetie. You were right. He's a fool if he can't see the goodness in you. He must never be allowed here. That kind of poisonous mind is far too dangerous."

Blossom didn't use the intercom that evening, nor in the morning, so after breakfast I tried buzzing it to see if she was okay. There wasn't a reply, which worried me, so while Jill went about the morning chores, looking after the gardens and the animals I went down to check that Blossom and the two children were alright.

At the door of the apartment in the parking garage I knocked. After there was no answer I tentatively opened the door a little and called out, "Hello? Blossom?"

She answered, "Kim?" and came out of the bedroom.

I was relieved and smiled as I entered the living room. "Oh, good. I was starting to worry. How's your little boy?"

"He's good this morning. We slept good last night. I tried to use the thing on the wall, like you said, but it didn't work. I think I broke it." She looked a little fearful.

Puzzled I asked, "Show me?"

She'd been misled by the power switch which had a small red light next to it, and had switched the intercom off, which explained why I hadn't been able to call her. I smiled and showed her the buttons for the buzzer and for talking and could tell from her mild panic that she didn't absorb what I was saying. She seemed to believe that she wasn't capable of understanding it. It was odd — what was so difficult to understand about pressing a button to make a buzzer sound, and another button each time you talk? But I shrugged it off.

Gabriel walked unsteadily out of the bedroom into the hall wiping sleep out of his eyes, saw me and stopped. He looked scared. Kayla stepped out of the bedroom too and lifted him into her arms. He was a bit heavy for her, but she held and comforted him noislessly. Blossom noticed my attention, turned and scampered to them, making cooing noises. She lifted him from Kayla's arms into her own, while giving Kayla a hug and a kiss on her forehead. "Remember Kim?" she asked Gabriel, "She helped you get better. She brung us here. We're safe now."

I gave them a smile, but he and Kayla continued to regard me with quiet shyness or suspicion. I regretted not thinking to bring toys of some kind with me.

"He's looking much better — no dark rings under his eyes anymore. Have you had breakfast yet?"

Blossom shook her head. "I woke up just before you got here. I didn't want to wake the kids."

I rubbed my hands together and led the way into the small kitchen. "Well, you're in for a treat. Jill put some yummy food in here. Let me make you some brekkie." I put out a couple of plates, peeled a couple of bananas and, using a fork, mashed them, then added a teaspoon of honey to each plateful, and mixed it up to a goopy texture. Turning to Blossom who was seated at the counter, with her boy on her lap, and Kayla glued to her side, all eyes watching me, I placed the plates and a couple of teaspoons before them. "I think they'll like this. My Mum used to give me this any time I was unwell when I was little. It'll help soothe Gabriel's tummy and give him some energy."

Blossom tasted it first and her eyes lit with approval, "Ooh! You'll like this, Gabe." She spoonfed him. I couldn't see any change in his manner, but Blossom murmured approvingly, "Oh, he likes that."

Kayla hesitantly at first, then hungrily, devoured the banana mix. Finishing by licking the plate clean.

It didn't take long for Gabriel to consume his either, so I asked if they wanted another. Blossom asked them gently, "Want more?" Again, I couldn't make out any response from either of the children, but she apparently could and smiling, told me, "Yes, please."

I suggested she might like a banana while I mashed another, so I handed one to her and peeled one for myself, showing her how to hold it by the unpeeled part while eating the peeled part. Then I put mine aside and mashed another two for the kids.

Kayla quickly devoured hers as before, but this time Blossom handed the other spoon to Gabriel. He clumsily grasped it and started to feed himself. I was a little surprised that he didn't get it all over the counter and himself, though a lot did end up around his mouth instead of in it. When he'd finished as much as he could manage, Blossom ate the remainder then licked the plate clean, as Kayla had done.

I asked if they wanted more and Blossom queried Kayla with raised eyebrows, and though the girl gave no response that I could see, Blossom smiled to me, "Yes, please."

I quickly prepared another and handed it to Kayla. She made short work of it, as before.

I rinsed a wash cloth and handed it to Blossom who lovingly cleaned Gabriel's face and hands with it. Kayla had remained scrupulously clean. I was going to offer drinks of milk to them, but I thought I recalled reading somewhere that it's not good for diarrhoea. Also, Blossom probably hadn't had milk since she was a child, so I guessed her stomach probably couldn't make rennin anymore to digest it easily. Probably the same was true of Kayla, so I gave them mugs of water instead. Blossom and Kayla were very thirsty. She said they hadn't known how to use the lever-taps. While they drank I washed the plates and spoons, Kayla's eyes following every movement.

Afterward, with Kayla trailing, Blossom took her son down the little hall to the toilet. While they were gone I set up the large computer screen to display a list of some of my favorite movies. I culled some of the more complex ones, leaving mostly innocuous romantic comedies and some cartoons.

When they returned, Blossom was holding Gabe's hand and was looking elated. "He's getting better very fast now. He's almost okay again." She sat on the main room's lounge and pulled her boy onto her lap, one arm around Kayla again, who was next to her.

"Glad to hear it. Well, you just rest. There's plenty of food and water in the kitchen. We'll bring you up to the main Habitat area when you're ready. In the meantime I've set up the screen to show some of my favorite movies." I pointed at the large screen. Then I held up the little tablet computer I used to control the screen. "Here's how you operate it."

I put the small tablet on Blossom's knees and noticed Gabe's and Kayla's intense interest in it. When I touched the play, pause, skip, next, previous, and volume controls the children's eyes followed every move. After running through a quick demo of how the controls worked I suggested Blossom have a go at it. She looked up at me helplessly and instead handed it to Kayla, who grabbed the tablet and deliberately and unhurriedly went through all the actions I had. I got the distinct impression she wasn't just mimicking me, but that she understood what she was doing. Gabe watched everything Kayla did.

Blossom smiled proudly, "Kayla's real good with things."

"Perhaps I should show her how you can use the intercom — the box near the door that lets you speak to us."

Blossom grinned and nodded, picking Gabriel up, to perch him on her hip, and with one arm still around Kayla, followed me to the intercom.

While I was showing them the intercom, pressing the buzzer button and explaining its function, Jill's voice came from it. "Hello? Blossom? Kim?" I pressed the talk button and explained to Jill what I was doing, then asked her to press the buzzer at her end so Blossom and the kids could hear it.

Next, I asked Blossom to call Jill. She stepped closer and Kayla reached up and pressed the buzzer button for a moment. Blossom started to speak, but Gabe, cradled in her arm, shook his head and placed his little palm over his mother's mouth. Jill answered, then Kayla pressed the talk button and Gabe removed his hand from his mother's mouth letting her reply to Jill, "Hi, it's me, Blossom." When she was finished speaking, Kayla released the button.

I laughed and pressed it again, "Jill, you should see these kids, they're amazing." They both avoided looking at me and clung more tightly to Blossom.

"They're shy," Blossom murmured, smiling and hugging them more.

I led them back to the lounge and showed them once more how to use the tablet to select whatever they might like on the large screen, then left them watching a gentle comedy.

Jill and I used the intercom to call them a few more times during the day and the evening to check how they were. Each time, Blossom told us they were "good", but didn't seem to feel the need to elaborate.

The next morning both Jill and I went down to the garage and knocked on Blossom's door. We waited until Blossom opened the door, welcoming us in.

Jill said, "If Gabriel is well enough to go through the decontamination we'd like to bring you up to the main living area now. We think you'll really like it up there."

"I think he's back to normal now," Blossom said, smiling down at her son who'd attached himself to her leg and was watching us silently. Kayla was attached to her other side, arm around Blossom's waist, she studiously avoided eye contact.

We led them out of the little apartment and into the decontamination room. We explained how it worked, and the importance of very thorough cleaning. Jill went through ahead to demonstrate. Gabriel went through with his mother. He hated the loud blasts of air, but didn't seem to mind the shower despite having never experienced one before. I couldn't tell whether Kayla liked or disliked it, but I noticed she was very careful to do everything exactly as we'd explained.

Soon we were all upstairs in the living-room, dressed in soft, white bathrobes. Blossom's, Gabriel's, and Kayla's eyes were wide and shining. We took them out into the fragrant garden where, at their puzzlement with all the sounds, we had to explain what birdsong and bee humming were. A couple of brightly colored butterflies zig-zagged past, almost within arm's reach. Small insectivorous wrens flitted about the branches of the trees and shrubs, feeding on insects. Ants hurried on their private errands across the concrete steps. A dragonfly zipped past, stopped in mid-air to hover for a moment before dashing off between the trees. The dogs, Gina and Toby, were playfully rolling on a grassy patch. Blossom, Gabriel, and Kayla stood there, transfixed. They'd never seen anything like this before. It must have been like another world to them. I guess, in a sense, it was.

We took them on a tour of Temperate-1, showing them the fruit and nut trees and other plants, giving them yummy samples along the way. After perhaps a couple of hours Gabriel was looking tired. Jill pointed out that we should probably get him back to the house so he could rest. There was plenty of time to see more later.

Back in the house, we showed Blossom and Kayla the other bedrooms. They selected one and we made up the bed. She put Gabriel down on the bed and lay next to him to comfort him, Kayla on his other side. Blossom smiled to us, "Go. I'll come out soon when he's asleep."

Jill and I went back to the lounge room and our customary position together at one end of the lounge. I put an arm around Jill, "We did a good thing, helping Blossom's little boy. I like Blossom. What would you think about her and the kids staying?"

Jill nodded, then said, "We did a good thing saving David too, but that kinda backfired."

"Yeah, but he's sort of broken — racist, a god-nut. Blossom's a good person, and it would be nice to have some kids here."

She smiled, "It would be nice, wouldn't it. Watch them grow and learn..."

I said, "One of the things I often worried about was us living out our lives, and after we're gone, the Habitat having nobody to look after it. All the animals here that depend on us..."

She said, "Yes, it had occurred to me too, but my greatest fear was of one of us dying and the other being alone. I couldn't bear the idea of losing you. I'm so lucky to have you."

Gratefully, I hugged her tight, and tilted my head up to kiss her cheek. She turned her head so her lips touched mine and we kissed gently, my tummy somersaulting as it often did when we kissed. Just then I caught movement out of the corner of my eye. Blossom and Kayla had emerged from the bedroom. I broke the kiss and released Jill. We moved apart a little, concerned at what Blossom's reaction might be.

Blossom grinned broadly, "Don't let me interrupt you lovebirds."

Jill and I were both red-cheeked. "Umm, no we were..."

"Uh, we just..."

Blossom waved her hands, "I'm sorry, please don't feel awkward. This is your place. I'm the visitor. You don't have to explain. If you can find love in this rotten world, then good on ya. Hang onto it, and don't let anyone change how you feel. Life's too short."

Jill breathed a big sigh of relief and smiled at me, "I see what you mean about her." To Blossom she explained, "Kim had told me how impressed she was with you after your conversation in the car coming from Noosa."

I asked, "How's little Gabe?"

"He's good — fast asleep." She frowned, "That's such a stupid saying. How can someone be fast when they're asleep?"

Jill said, "You'll want to stay close by, in case he wakes." She indicated the lounge chairs.

I asked, "Can we talk about who in Noosa you think might be suitable to live here?"

Blossom nodded, walked over, indicated for Kayla to sit in one of the chairs and settled into another herself. "Jeez, these chairs are nice." Then she thought for a while, frowning. "About half of them believe in their nutty god. I mean, they're mostly nice people, long as you don't cross their beliefs, then they become a real pain in the arse. But only five are really crazy god-nuts. Another, ummm..." she counted on her fingers, "two believe in a god without it running their lives. They just do what the nutters say. Three kinda believe in god-shit, but ignore the nutters. The two kids, Kayla and Gabe, are too young to know or care. Maria, Vincent's daughter, is about my age, and couldn't care less about it. Just five of us think the god stuff is dip-shit stupid." She grinned. "We should be looking after each other, not praying to some weak-as-piss, bullshit, imaginary spirit-thing so we can go to heaven. If a god was going to do the right thing it would have stopped the bastards who made us slaves and wanted to eat us. It can't do that, so it's not much use. Can go screw itself... 'cept it's obviously imaginary, so it can't even do that." She flashed a mischievous grin.

Jill and I laughed.

I said, "So about half might be okay to live here?"

Blossom nodded. "I wouldn't trust the very religious ones. I mean, they're mostly good, even the crazy ones, but people are not their top priority, ya know? Their imaginary god always comes first, and people are expendable. They're way too quick to assume problems are sent by their god, so they accept them instead of trying to fix them. Like Gabe's sickness. They thought it was god getting back at me for not believing. I mean, how stupid is that? What kind of dipshit god would hurt a parent by making an innocent kid sick? Idiots."

Jill said, "Okay, so that's eight non-religious people — you and the kids, Maria, and the four who think like you. That makes the pressure on the Habitat and our food resources a lot easier to manage."

I asked, "What about the less religious ones? Are any of those likely to turn into bullies? You know, try to take over, the way the bosses in Caloundra did?"

"Well, maybe two, but it wouldn't come to that, because they're partners of believers, so they wouldn't come without their lovers. In the end, maybe, ummm... only three would be safe to bring — Ben, Dahlia, and Matt."

Jill nodded, "Then we should work out a way to bring them here without upsetting the others in Noosa and without affecting the whole group's chances for survival."

I said, "It would probably be good to leave it for a while, so that everything settles down first."

Jill agreed. Blossom asked, "How much is a while?"

I shrugged and looked at Jill, "A week? Two weeks? They're safe. They have plenty of food. If they need to contact us they have the radio..."

"Fair enough," Blossom nodded.

Jill asked, "Would it wake Gabe if I played some music?"

"You mean sing? No, he'll sleep right through that."

I said, "No, Jill means play some music on the computer." Then I demonstrated by using the tablet to send the instruction to the house computer to play one of our favorite trance music playlists. I made sure the volume was turned down somewhat, so as not to disturb the sleeping child. I noticed Kayla's eyes followed everything I did with the tablet. I made sure I tilted it her way to make it easier for her to see.

Blossom's eyebrows raised. "That's music? Huh. Well, I guess it's kinda catchy."

I got up and fetched four apples from the cool room, bit into one, threw one to Jill, and offered the other two to Blossom and Kayla. Blossom said they'd never had apples before, so I explained the art of eating it and leaving the core.

After Jill and I had finished our apples, I said we'd better get our chores done. I showed Kayla and Blossom how to turn off the music using the tablet if she got sick of it, and we left with the dogs. I was towing the little basket-trolley with empty milk bottle, biscuits for the goats, and grain for the chooks.

When we were well beyond hearing distance from the house Jill said she was having difficulty trusting Blossom and any other people from Noosa, 100%. I understood what she meant. I liked Blossom, but the experience with David had soured things a bit and left us both feeling a bit wary.

We did the rounds of the environments, including a quick visit to check on the two aquatic ones. We descended the stairs near the airlock to the underwater labs and checked the measurements — suspended solids, pH, conductivity, temperature, dissolved oxygen — and looked at the computer's automated count of fish. Everything looked stable, so we headed back to Temperate-1 with our basket full of fruit, veggies, and goat's milk.

Gabe was awake and slightly less shy, though still clinging to his mother. Kayla had the tablet computer, was exploring it and ignoring us. The music was still playing. Blossom said she'd found it oddly enjoyable so had left it playing.

Jill asked, "What have you been doing, Kayla?"

She avoided looking at Jill and continued to do things with the tablet. Blossom said to her, "Go on, honey. Show Jill what you've learned." Still avoiding Jill's eyes, she paused the music, turned the large video screen on, and played a short video of a cat chasing a light spot from a torch around a room. Blossom chuckled at it. Next, Kayla selected the house control overrides and turned the lights up and down. Then she dismissed the control interface and opened Gimp, the graphics program. She created a new, blank image, then using her finger, quickly drew a shape which looked like a squashed and distorted loop, and filled it with black and a couple of gray highlights. With a shock, I suddenly realised it was a drawing of Gina lying on the floor a couple of meters in front of her. I tapped Jill's shoulder, and when she looked at me I mouthed "Gina" and pointed to the dog. Jill's eyebrows went up suddenly, as she realised how accurate the drawing was. It had perspective and foreshortening, without any attempt to draw what she thought was there... just what was there. I fancied myself a bit of an artist, and I'd tried to show Jill how to draw, so I knew this was unusual.

Now she closed Gimp, not bothering to save the image, and opened a short text document Jill had been writing some time ago, trying to come up with ideas for destroying the rogue algae if it ever contaminated the Habitat. Then she popped up the menu and chose the mouth icon and the tablet started reading the document aloud. When it had finished, she closed that document and stopped. She glanced at Blossom.

"That's amazing," Jill said. "How long has she been using a tablet computer?"

Blossom smiled proudly, "Yesterday's the first time she ever seen one. We never had 'em at Caloundra."

Jill looked at her in surprise. We didn't know it then, but we would one day owe a great debt of gratitude to those two amazing children.

That night, after we'd eaten, while the five of us were watching a light comedy, the radio spoke up. We almost didn't hear it because the voice on the other end was speaking quietly. I paused the movie and hurried to the radio. We'd put it on top of the waist-high shelves on the back wall opposite the glass doors. The voice on the radio was repeatedly asking in a hushed, but urgent voice, "Is anybody there?"

Blossom said, "That's Charlie. What's wrong, Charlie?"

Pressing the speak button I answered, softly, matching his tone, "Yes, we're here. Is there a problem?"

Charlie said, "I can't talk very loudly or they'll hear me. David and a few of the others have got an awful idea. They say you folks are preventing their god's plan from being carried out. They say their god made an Ark for the righteous and that you're stopping them from inheriting it. Guess who they think god's righteous people are." He snorted derisively. "They're going to fake an emergency to lure you here tomorrow morning and if they can't convince you to take them to this Ark then they'll steal your car, stranding you here. I wouldn't put it past them to use violence. This is the thanks you get for saving them."

Jill, who is generally a quicker thinker than I am, said, "Thanks Charlie. Tomorrow, when they call, we'll come, but we'll go to the supermarket near your place instead. When we're there, we'll radio to say we're still coming, but that we've been delayed a little. In the meantime, you tell the others you want to make a trip to the supermarket to get some things. Bring only the very few people you're absolutely sure won't hurt us and try to take our home from us. We'll meet you at the supermarket."

I added, "Thanks for warning us, Charlie."

"No worries. It's the least I could do. You've gone out of your way to help us all. You don't deserve this. I wouldn't blame you if you just left us here and never had anything to do with us again. That's probably what you should do. We're already way better off than we were before. You really don't owe us anything. We owe you."

Jill said, "Human life is far too valuable. We all need to help each other. That was always true, but since the disaster it's even more--"

Charlie interrupted with a hurried whisper, "Gotta go." And the radio was suddenly silent.

None of us spoke for a little while, then Jill turned to Blossom and asked gently, "Tell us about Charlie."

"He's a good guy — reliable. He looks after weak and sick people. His Mum and Dad were doctors. They've been dead for some years. He doesn't believe in gods or spirits. Ummm... can't really think of anything else. Oh yeah, he tried to teach me to read and write, but..." she shrugged and gave a lopsided smile.

Jill said, "Who might Charlie choose to bring? Do you have any idea?"

Blossom thought for a bit, "Well, definitely Vikki, she's his partner, and their young boy Cliff... well, not so young anymore. Probably Vincent and his daughter Maria. Maria's about my age. Her mother died giving birth to her. Probably Ben. Maybe Dahlia. Maybe Matt. Those last three believe in a god, but they're good reliable people. They're not obsessed like David and the other four nut-cases." She paused. "Michelle would tell David, and won't leave him anyway. Likewise Lara. They're both good people, but they'd stay with their crazy partners. I don't think Charlie would trust either of them."

I'd been keeping count on my fingers. "That's a possible maximum of eight people." I looked at Jill, "We'll have to take the van again."

Jill said, "Can you get it ready before sunrise? I'm not keen on driving in the dark, but if we start long before they radio us, then we can be at the supermarket earlier than anybody will expect, and watch the approach of those escaping to make sure nothing bad is happening."

Blossom looked puzzled. "Bad?"

"If David overheard Charlie's call to us he could maybe set up a trap at the supermarket, or... I don't know." Jill sighed. "I'm just becoming very suspicious. This is all getting dangerous and I'm getting tired of it. I just want to make sure nothing goes wrong."

I asked, "Blossom, can you come with us? I can identify David, but not the others. We'll have to rely on you to tell us if the people are okay or not."

Blossom agreed.

We went back to watching the movie, but I doubt anybody enjoyed it. We were probably all thinking about the many ways things could go wrong tomorrow. I know I was.

* * *

part 8 - foil

I was up before well daylight and went down to the garage to get the van ready. It felt strange to be there so early in the morning. The garage was unchanged — just as large and echoey, and lit the same as always, not having windows to the outside, but the unusual time of day somehow gave it a strange, unfriendly feel. I didn't need to do much, other than the usual checks and installing a radio in the van again. Everything was still in good order from the last time we went out to rescue the group from Caloundra. I filled some personal air canisters, charged up the supercapacitor banks, and moved the oxygen concentrator from the car to the van. As I was putting the finishing touches, Jill, Blossom, and Kayla appeared, with Gabe on Blossom's hip.

I was surprised. "You're bringing the kids? I'd have thought they'd be safer here."

Blossom said, "They didn't want to stay on their own."

I nodded. "I'm almost ready."

Jill suggested to Blossom that she, Kayla, and Gabe might want to use the toilet in the garage's apartment before we leave. The van had a simple toilet, but it was pretty limited, and we didn't know how long we'd have to wait out there, though hopefully we'd be back before midday.

When they were in the little apartment, Jill stood close to me, biting her lip worriedly, and bowed her head, eyes closed, "I have a horrible feeling about this."

I gave her a quick hug. "If we're careful we should be fine." I didn't want to admit that this scared me too. I actually felt like staying home and avoiding the whole damn thing. We'd already gone out of our way to help these people. Where did it say that we had to keep putting ourselves in danger for others? But I knew the answer to that. We had to help. I wouldn't be able to look at myself in the mirror if I didn't.

We had to travel very slowly until dawn. Even with extra floodlights on the van to illuminate the road, we could only manage a slow crawl. It would be far too easy for a minor accident to strand us out here — a death sentence.

When the cloud-wrapped sky began to lighten, we were only about twenty minutes away from our destination. Daylight made the journey much easier and less stressful. When we were finally within several blocks of the apartment building we took a widely circuitous route to the supermarket so that we couldn't be seen. We parked under some trees, partially obscured by bushes, near what was once the supermarket's large car park. Here, we could watch the path that connected the apartment block and the supermarket. We were only there for about half an hour when the radio call came. David must have wanted to get an early start to lay the trap. He said the electricity had failed and that they were using a small battery to run the radio. Could we come and help before they ran out of oxygen? I was tempted to ask how he'd had the foresight to charge a battery beforehand, but I refrained.

Jill said, "Okay, it'll take us about two hours to get there. See you then."

We waited several minutes and radioed them to say we'd been delayed, so would take a bit longer getting there. We hoped Charlie got the message, made his excuses, and left with his friends. We would know soon enough.

About ten minutes later we saw eight figures walking along the path toward the supermarket. I handed the binoculars to Blossom and asked if she could tell who they were. After initial clumsiness with the binoculars, and despite the people's hats, goggles, and masks, she identified each of the people by name. They were exactly the ones she'd listed last night. We continued watching for a little while to make sure they weren't being followed, then drove the van up to them before they reached the supermarket. It took an agonising several minutes to load them all into the van through the little airlock. When it was done, we were on our way back to our home.

Like Jill, I had a nagging feeling of uneasiness. When these people were at the Habitat there was no undoing this. We had been alone and had led a quiet existence for decades — most of our lives — secure in each other's dependability. Suddenly, over the past few days we'd had to deal with a surprising number of people who endangered our existence. First the cannibal cook when we rescued Michelle, then the scary, unseen slavers who we rescued these people from, then the slavers again and, surprisingly, David when I went back with Michelle to rescue him, and now David again and the other religious ones who thought their god wanted them to steal the Habitat from us.

While Jill drove, I explained my worries to them. They did their best to reassure us that they were deeply grateful and that they would never betray our trust the way David and the others had. They seemed sincere. I still had nagging fears, but did my best to swallow them. We were now committed. There was no going back from this.

When we were well clear of Noosa I radioed David. When he answered, I said, "You should switch the electricity on again, because we're not coming. We know it was a lie to betray us and steal our home. You are not a good person, David. Eight of the others agree and are with us on our way back to our place. Good bye."

Blossom looked puzzled, "Why did you tell him all that?"

I said, "I didn't want him to leave the electricity off too long. Low oxygen levels are dangerous. And I didn't want them going out looking for all of you, unnecessarily exposing themselves to risk."

Blossom said, "After all that, you're still concerned for them? Wow! And I would have said something way stronger than he is not a good person." She laughed.

I shrugged and smiled, embarrassed and unable to think of anything to say.

We never heard from the seven left behind in Noosa again. We don't know what happened to them. When we cautiously investigated their radio silence many months later, we found everything neat and functional, with no signs of any struggle, but nobody there. After much conjecture, we wonder if perhaps they mass-suicided, perhaps at the seaside, which was just a short walk from there. Perhaps they'd been under the delusion they were going to meet their god. Instead, they were wasting the two most precious things in the universe: life and intelligence.

After all these years I still wonder if there was anything we could have done to alter that sequence of events. It's a pity David took six people with him. I know that really, it was a good thing that his treachery was exposed so early. I've seen videos of people with fundamentalist religious beliefs and I don't think we could have ever trusted him. Such beliefs seem not to be amenable to new information. They don't allow for reality; they require reality to be bent to fit them.

I always felt sorry for Michelle, and guilty about abandoning her. But as Jill pointed out to me, Michelle made her own choice. The place at Noosa was safe and secure; she and any number of them could have continued to live there. We didn't abandon her. We did everything we could to help her. It didn't help me feel any better, though. Even now, after all these years, I keep imagining how she must have felt.

She saw, touched, and walked around inside our Habitat, which must have seemed like paradise, but felt compelled to abandon everything for an imaginary, cruel god. Did she feel betrayed at the end? Bitter? Or did she keep the blindfold firmly in place to the end? Did she suffocate with a happy expectation of an imaginary heaven? What a waste.

* * *

part 9 - people and spiders

We needn't have worried about the eight people we brought to the Habitat — well, eleven if you count Blossom and the two kids. Over the ensuing weeks and months they all fitted in well and proved to be lovely people.

Ben helped everywhere that he could. His extensively scarred face and arms made him look ferocious and dangerous, but he was the exact opposite. His special skill was a buoyant personality that kept everybody happy. He always came on scavenge expeditions. His strength, agility, and upbeat optimism were always great assets. He occasionally took unnecessary risks when his fearlessness made him reckless, but he never put anybody else in danger, and he always brushed off any personal injury with jokes. I sometimes wondered if his belief in an afterlife was what made him so reckless. Jill didn't think so. She thought it was simply a part of his personality; he didn't intellectualise, he just did things without considering the potential for damage to himself. I found it puzzling because he would always take great care to ensure other people were safe.

Charlie, his wife Vikki, and their son Cliff, attended to everybody's health, including that of the animals. They gratefully immersed themselves in the computer's vast library of medical information, quenching a deep thirst. Cliff was in his late teens. He became obsessed with genetics and spent most of his time in the biology laboratories trying to find a way to eliminate the rogue algae. Jill often talked with him about that, since she'd long pondered that problem too. Personally, I didn't like the chances of doing so — how do you get rid of something that's the most successful lifeform on the planet? I said that to him once and Cliff smiled and replied, "The most successful lifeform is just the most unexploited food resource for other living things."

Vincent was tall and thin, a little bent over. In his seventies he still had a full head of scraggly white hair. He'd studied as an engineer before the catastrophe. With the aid of the computer's library and machine shops he made a number of good improvements to the Habitat. He was the one who'd modified the oxygen concentrators for the slaver group. With the tools of the Habitat's workshops now available to him he made further improvements to them. He'd thought of the alterations years before, but his primitive environment had made such changes impossible. I worked with him to equip each of our vehicles with them so they no longer needed bottled air, extending our range tremendously. He also began the construction of much bigger oxygen concentrators for each of the environments, just in case rogue algae contaminated the Habitat.

He'd passed on much of his knowledge to his thirty-something year old daughter Maria. She redesigned the oxygen concentrators, reducing their size so they could be carried on our belts instead of air canisters. This made our movements outside much safer and gave us much more freedom.

Maria and young Kayla spent a lot of their time learning as much as they could from Vincent. I did too, but was humbled by their rate of learning. The three of us helped him where we could. With the Habitat's computer system at our disposal, we wrote notes on everything we thought might be relevant. Vincent wanted to save as much of his practical knowledge as he could. He was planning for the future when he wouldn't be here to help. He often growled in his frustration at the decades obscenely wasted under the stupid slavers. So much more could have been achieved; so much time had been lost. Over and over again he expressed his gratitude to Jill and me for giving him the opportunity to do something really positive with the final part of his life.

Dahlia and Matt had an unexpected skill and passion for gardening, taking most of the load off Jill and me. Jill taught them what she knew (she knew far more than I did about gardening) and we showed them how to look up information in the Habitat's computer library. With the extended range that Vincent's new oxygen concentrators gave our vehicles, and Maria's small personal ones, we took Dahlia and Matt on explorations far afield to old farms to find new useful plants, which, after careful decontamination and some months of quarantine, were added to the Habitat, significantly boosting the diversity of plants available to us.

Blossom's little boy, Gabriel, turned out to be a sponge for all kinds of knowledge. Vincent gave him an extraordinary engineering education. Charlie, Vikki, and Cliff answered his never-ending questions about biology, medicine, and especially genetics. He would badger Dahlia and Matt with queries about gardening, until they reached the limit of their patience, and he would go and read information, watch educational videos, and listen to talks from the Habitat's computer.

But much of the time, Gabriel and Kayla were inseparable. On a number of occasions I had the opportunity to watch them. Kayla would silently work on something while Gabriel would look on. He would sometimes make suggestions and Kayla would usually stop and think for a little while before either accepting it with a nod (great praise from Kayla), or rejecting it with a careful and patient explanation of why. Sometimes I wondered if the explanation was more for her own benefit than for Gabriel's; it was almost as if she was talking to herself (which she would often do when working through problems alone). Gabriel would always listen intently to her explanations. There was never any contest between them. Ego never intruded. They accepted each other totally and never felt threatened by anything the other said. It was all about whatever they were working on. They both just wanted to learn and create. It was inspiring to see. I always felt very privileged to witness it.

Kayla was definitely an oddity. Her parents had been killed by the slavers when she was only four, and she'd become attached to Blossom. When she came to live with us she was only about ten years old, and very quiet. She gave the impression of being shy, but I realised after a while that she was actually very sure about the things around her. She just rarely felt the need to speak. She was fascinated by our computers, especially the one that controlled the Habitat. She quickly taught herself to write programs.

A couple of weeks after she'd arrived here Kayla came to me and asked, "I was reading in the journals of one of the engineers who used to work here, that you have some CNC machines." She added, glancing at me, "Computer Numerical Control machines — cutters, grinders, 3D printers--"

I nodded, "Yep, I know what CNC machines are."

"Can I see them?"

I thought for a moment. "Okay," and beckoned her to the back of the living quarters and the stairway that led down to the labs underneath. "What do you want to do with them, honey?"

"Nothing yet. I just want to understand them."

We walked through the labyrinth of underground passages to the engineering section, then into the large CNC workshop. She was awestruck. Eyes wide, she stood for a while just taking in the room. Then went to each machine and reverently examined it while I described it, its special advantages and shortcomings, and the safety procedures that had to be followed.

She was most fascinated by our 3D printers, particularly the one that used a plastic filament. I explained how she could design an object on the computer and in a short while, perhaps minutes, depending on size and detail, be holding the physical object in her hands.

She asked in her quiet voice, "Can you demonstrate it?"

As it happened, I used it more than most of the CNC machines so it took me just a short time to select from the object library a small decorative 3D model of a bird with wings spread, load the file into the computer and send it to the 3D printer.

I explained, "The printer's computer breaks the file down into slices that, when printed one on top of another, make the final object. It's already loaded with PLA filament so we'll use that."

She murmured to herself, "Polylactic acid."

That surprised me. I soon came to expect the unexpected with Kayla. I continued, "I've set this to print at a fairly low resolution so it'll be quick."

Kayla watched the machine's every move as it built the pendant. It only took about a minute, so was quite rough, but when I lifted it off the plate and handed it to her she actually smiled. This was one of the few times I ever saw Kayla smile — not the subtle, shy, blink-and-you'll-miss-it smile she sometimes gave. This was a full-strength beam that lit up her eyes, a very rare event.

She asked, "Can I print a high resolution one?"

"Sure. It'll be much slower. Would you like to use multiple colors too?"

She nodded eagerly. I let her make the changes and send the modified file to the 3D printer. She left the computer and stood, as before, at the printer, watching every move. When it ended I let her lift the little blue and white bird from the print bed, cautioning her that the bed was hot.

Pointing to the laser cutter, I asked her, "Would you like to make a clear box for the bird pendant?"

She nodded, so I first showed her how to make a design on the computer (I used an existing one for my demonstration), then I got her to load some three millimeter thick acrylic sheet into the cutter and shut the cabinet cover. "You have to make sure the cover is firmly shut or the laser won't operate. It's a safety lock to make sure the laser doesn't accidentally damage the user's eyes by operating it with the cover open."

When the machine had finished I let her open the cover, remove the acrylic pieces, and peel the protective paper off them. I was going to show her how to snap the interlocking pieces together to form the box, but she already understood and immediately did so without a word from me, placed the little pendant inside, and closed the hinged lid.

There was only one other that she really wanted to try: the metal sintering 3D printer.

She asked, "Can it make a chain?" When I nodded, she asked, "How fine?"

I didn't know the answer to this. I mainly used it to make fairly large mechanical parts for the vehicles. I searched for "resolution metal sinter 3D printer" in the documentation and came back with 0.3mm. "That might be fine enough for what you want, but it might be impractical because of all the support standoffs that would be needed. It's probably more efficient to make a chain the old way."

After a moment's thought Kayla designed a chain where all the links lay flat, but were twisted a little at each end. No supports were required. So we printed her design in silver powder.

When it was finished, I asked her to put on the mask and gloves next to the machine and gently use the brush to sweep aside all the unused metal powder so she could lift up the chain and clean it. It was a pretty chain and the slight twist at the ends of the links caused the chain to fall into a helix. Kayla was obviously very proud of it.

We did the rounds of all the other machines, but she didn't like the noise or waste of the router mill and grinders, or the lathe. I have to admit I was glad of that because those machines were also the most dangerous and I told her that if she wanted to use them I had to be present. She was welcome to use the plastic extrusion and metal sinter 3D printers and the laser cutter any time though, so long as she was careful. "Safety first!" I emphasised. "We can make lots of things, but we can't make new body parts."

"Yet," she added, giving me a flicker of a smile.

When I next saw Blossom, she was wearing the bird pendant on the chain. Kayla had given it to her as a present. I have to admit I smiled and my eyes teared up a bit at that.

A couple of days after that, Kayla had built a hand-sized, spider-like, robot toy for Gabriel. Blossom had proudly told me afterward how Kayla had presented it to Gabriel. The two kids had sat on the floor of the bedroom and Kayla had carefully explained to him how it worked, disassembling and reassembling it to illustrate. He had listened patiently through the entire sequence. At the end, Blossom had prompted him, "What do you say to her, Gabe?" He'd thanked her and she'd given him a fleeting, shy smile.

Blossom and Jill and I had initially wondered how much Gabriel had absorbed — he was, after all, only two years old — but it was soon clear he understood it entirely. Over the subsequent days and weeks he made many suggestions to Kayla, inspiring her to create a succession of small spider robots, each an improvement on the previous one — more robust, yet lighter, faster, with smarter programming, more maneuverable, and with better sensors. The first ones had all their programs onboard the little machine, but later ones were radio-controlled by programs running on the Habitat's main computer. This let Gabriel control it from a tablet.

About a month later, Ben had an accident while cleaning the exterior of one of the domes. He slipped while ascending the steep edge. His harness saved him from what could have been a very serious injury and he was only bruised and shaken up. Everybody talked about it around dinner in the main room that evening. Those meetings had become informal discussions where we analysed and digested the day's events. Ben joked and laughed dismissively about it, but we all knew how dangerous it had been. Kayla silently listened to our conversation, as she always did.

It rained heavily for some days after that, so the job of cleaning the domes was postponed for better weather.

A few days after Ben's accident Kayla came to the evening meeting followed by another spider robot. This one was much bigger than the ones she'd made for Gabriel. It was about a meter across and, like Gabriel's spiderbots, controlled wirelessly. She said in a soft voice, without looking at anybody, "Now nobody needs to risk cleaning and maintaining the domes."

At that point we were starting to see how valuable Kayla would be to our community.

She made more of the robots in the ensuing days and weeks. I suggested some minor improvements from my experience over decades of cleaning and repairing the domes. (Jill's fear of heights kept her on the ground controlling my safety line.)

But the day after Kayla brought that first spiderbot along to dinner we put it to work finishing the cleaning Ben had begun a few days before, when he'd had his accident. It was marvellously quick. From inside the Habitat we all watched it crawling methodically over the dome in the rain, cleaning each clear panel, one by one. It was much quicker than a human, and far safer. The spiderbot also increased our electricity production because we put it to work cleaning the solar panels too. That evening we all threw a party to celebrate Kayla. During the party, she was as quiet and withdrawn as she always was, though evidently pleased.

Late that night, when Jill and I were in bed, talking, Jill said, "I've been thinking about how amazing these people are, and what they've accomplished in just months. For decades the slaver-cannibals had remained at mere subsistence level by dominating them. The religious extremists in Noosa were doomed by their delusions to never advance. But here everybody has autonomy, and it took just a brief time for them to flower."

I said, "It helps that we have lots to share."

"True, but I can't help wondering what the slavers could have achieved if they'd treated each other as equals instead of being petty rulers. I mean, look at the talent they had at their disposal. If they'd persisted in building an indoor garden with an oxygen atmosphere they would have had more success with plants. There are still libraries with paper books, and computers are everywhere, as well as 3D printers. Almost every building had solar panels before the catastrophe. A lot of them degraded, but a lot didn't. They could have built a thriving colony. Instead, they just survived."

I agreed. It certainly was something to think about. The Habitat had benefitted greatly from the skills of these people. Exactly the same people who'd eked out a miserable existence under the brutal dictatorial rule of a bunch of greedy, controlling bullies — bullies who would never think to share their fortunes with those they ruled over.

Jill said, "It's amazing that they survived all those years. It must have seemed so bleak. The future would have looked awful. It would have looked like there was no way to escape — nothing to look forward to. It's astonishing that they clung to life in those circumstances."

I pointed out, "I don't think it works like that. There's no shortage of past examples of people living through similarly awful things: concentration camps, thousands of years of slavery, religious indoctrination, the exploitation and genocide of the original Australians, abuse of prison populations, especially in third world countries, the treatment of the poorest people everywhere in the world right up to the catastrophe..."

She pondered that for a little while. "We're so privileged to have our upbringing... When I compare it with what these people went through, the difference between their experiences and ours is such a vast gulf... it's mind-numbing."

"We have been incredibly lucky — loving parents, wonderful educational atmosphere among the Habitat scientists and engineers, and then after everything," I caressed her cheek, "we have each other."

"And now," she added, "all these wonderful people."

We happily snuggled together to sleep.

* * *

part 10 - horses, birds, trees, ants, and slugs

Vincent insisted that it wasn't safe to use just one vehicle on scavenging trips, and that we needed at least two for redundancy. This made good sense, so we started using the car plus either the truck or the van on scavenging trips.

A few months after his arrival, Vincent wanted to go on a scavenging trip to Kunda Park to look for some engineering materials and supplies in the old industrial area there. Ben accompanied him in the truck and Maria and I were in the car leading the way. It was a good day for travel as the light was bright through the perpetual cloud cover, and the temperature, though always hot and humid, was not as terrible as it usually was. A strong breeze was blowing from the coast. The wind was hardly noticeable until we reached the top of the mountains at Mapleton. It waved the tops of the trees, and in the few open areas, the lower bushes too.

When we arrived at Kunda Park we scouted the area on foot. It was surprising how little vegetation was growing inside the buildings. We often had to hack our way through scrub and jungle that had grown up around them through what had presumably once been gardens, lawns, and some unpaved driveways, but inside the factories and workshops we could wander freely. The surrounding trees protected the buildings, except where a branch had fallen through a roof or the increasingly violent winds had blown a tree over onto a structure. Many of the dim interiors looked like they'd been abandoned only days ago. Metal was barely corroded. Tools were sitting, waiting for people to pick them up and use them again. The most jarring thing was when we found a few forlorn skeletons of people who'd stayed at their work to the end — depressing reminders of the cost of the catastrophe.

Over some hours we loaded both vehicles with lots of valuable goods — sheet metal, boxes of bearings, welding rods, some enormous supercapacitors, and much more — and headed back the way we'd come. Travel on the connecting roads was slow because the surface was in such bad shape, but the highway had remained relatively clear of vegetation, so we used that when we could and naturally drove faster there. However it had not escaped damage either, and that day on our way back, with the added weight in the car, I drove over a deep crack hidden by a broad drift of leaf litter. There was a loud bang! The car yanked suddenly left. Momentum, the extra weight, and high wheels rolled it over, breaking the windscreen and skidding to a stop on its roof. Hanging upside down in our seatbelts, Maria and I hurriedly put our masks and goggles on as the outside wind mixed carbon dioxide-rich air in, stinging our eyes. In just moments Ben and Vincent were helping us out of the car. The right side of my head was bleeding where it had hit the door, but I was a little surprised that I didn't feel any pain. Later my head and right shoulder would ache badly, but at the time I guess my body's endorphins had kicked in.

Shaken, we climbed into the cabin of the truck, and while Vincent examined the car, Ben radioed home to ask Charlie and Vikki about my injuries. With their guidance, Ben carried out a few quick tests before deciding we were probably okay.

Vincent returned to the truck to tell us that we would have to leave the car for now and come back for it another day. The axle on one of the front wheels had broken and we didn't have any easy way to roll the car right way up again. Ben salvaged some of the things from the car first, then we headed home.

At that evening's meeting/dinner when we recounted the day's events, we were all chilled by our understanding of how badly that could have turned out if we'd travelling in just one vehicle alone. It made Jill and me look back in horror at how incredibly dangerous our scavenging trips had been over the preceding decades. So many things beyond our control could easily have gone wrong and we would have died out there, just the two of us, helpless.

After that, we were determined to add to our fleet and recovered several more electric vehicles. We refitted them with larger wheels, sealed them to be airtight, and added oxygen concentrators to them. The poor broken hatchback was left, upside down, on the highway after we stripped anything useful from it. Funny how you can become attached to a piece of machinery. The car had served Jill and me so well for decades. We somehow felt disrespectful, leaving it like that.

Scavenger trips then became convoys of three and four vehicles at a time. Unfortunately, vehicle troubles became increasingly frequent too — not because the machines were less reliable, but because the roads were deteriorating so badly and we were exploring so much further afield. In many places roads had disappeared entirely, cutting off large areas from us.

After one particularly trying week of transport problems, one after another, on increasingly impassable roads, beset by heavy rains and strong winds, we all came together in the main living area for our usual dinner meeting. Dahlia and Matt were the last to arrive, as they'd been putting in some new vegetable gardens in the Temperate-2 dome. When they arrived, Vincent said, "Okay everybody, before dinner I want you all to follow me down to Engineering to see something Kayla came up with. Maria I have been working on it with her."

Vikki asked, "What is it?"

Vincent said, "I'll let Kayla show you. It's her idea. She's waiting there for us."

I looked at Blossom. She was grinning. She obviously knew what the surprise was.

Vincent led the way down to Temperate-1's largest engineering lab. When we arrived, there was no need to ask what we'd come to see. A large, six-legged vehicle stood before us in the lab. It was barely taller than a person and only a little wider than a person. Kayla was seated snugly inside the front of a small capsule shaped like an elongated egg. The upper surface appeared to be covered in a mosaic of small solar panels. The top front half was lifted up at the moment and was transparent, but with solar panels forming louvres that would shade the interior while allowing the pilot to see out. Behind her the larger part of the capsule looked like it was large enough to seat another person with room for luggage. The bottom half of the capsule was fixed to the six legs. Each leg had three joints and ended in a rounded foot that looked a little like a cow's split hoof about the size of your two hands, side-by-side, flat on a surface.

Kayla left the top of the capsule up, presumably so we could see her actions, and went through a number of demonstrations while Vincent explained, with occasional comments from Maria, clarifying points.

Kayla pushed a joystick forward slightly and the giant insect took a step toward us. A laugh rippled through her audience as a few people stepped backward nervously. She then pulled the joystick back gently and it took a couple of steps backward.

Vincent explained, "The vehicle is very maneuverable. It has a fair amount of computer programming onboard so it can be steered with just a single joystick."

Kayla then pulled the joystick to the left and the vehicle took a couple of steps sideways to the left, then right and it stepped sideways to the right. Next she twisted the joystick clockwise while keeping it vertical. The vehicle turned on the spot to face right. She twisted it counter clockwise and the vehicle turned back to face us again. Now she pulled back a little, making it step back a bit, turned the vehicle a little to the right, then pushing forward slightly while twisting the joystick, made the vehicle walk forward in a circle, like an ant walking around the lip of a bottle.

When she'd finished the circle she didn't re-orient toward us, but continued to face to our right, where a lot of boxes, benches, tubes and other things took up much of the enormous workroom. Now she directed the vehicle toward that obstacle course.

Vincent said, "The vehicle's body has several cameras mounted so as to let it intelligently negotiate uneven terrain. All the pilot need do is indicate where they wish to go. We got a lot of help from actual code we found in some of the scavenged university hard drives. There is some great work on self-navigating robots there."

The machine performed amazingly, stepping over objects and up onto benches when directed to, then back down onto the floor. At one point Kayla even made it step backwards onto a bench and turn about with tiny steps to face in the opposite direction before stepping off onto the floor again.

A pipe about as wide as a person's arm had been slung from the ceiling at about head height over on the far right side of the room. Kayla directed the vehicle toward it and pulled the mirrored lid of the capsule down, hiding her. About a meter before the capsule would have collided with the pipe, the legs bent in a squat, while continuing their forward motion.

Vincent said, "Kayla didn't need to tell it to do that. It watches for potential collisions and does what it can to avoid them, but it is far from perfect at it. The pilot has to be careful with overhanging branches and low objects that could trip it up."

Maria added, "If it does detect that you've directed it to do something unsafe it will refuse to comply unless you press an override button. The override is just in case the pilot gets in a dangerous position where they have no choice but to take a risky action. Normally it should never be needed."

Kayla had raised the canopy again and walked the vehicle back to its original place before us, pressed a switch, and the vehicle gently settled down to the floor, folding its legs under it in a way that reminded me a bit of videos I'd seen of camels. Kayla stood and vaulted out over the side.

Vincent said, "The fact that it can safely cover uneven ground means it isn't restricted to roads. Being narrower than our cars and trucks, we're expecting it can even walk through forest. The long legs let it step over logs and shrubs, and even wade through creeks."

Maria said, "The legs use pneumatic power — air — instead of hydraulics or electrics. This means they don't have to be protected against shorting out in water or leaking liquid if tubes are punctured. They can be easily patched in the field and continue working safely to bring you home, where they can be repaired properly."

Ben asked, "Why six legs?"

Vincent answered, "They help with stability and give redundancy, letting it walk even if one of the legs is damaged. It could even manage with two damaged legs, so long as they weren't on the same side."

Maria added, "If two legs are damaged on the same side, it can still stand stably while you remove one of the damaged legs and replace it with a working one from the other side. The legs are modular and interchangeable."

Everybody wanted to have a try at driving the vehicle, so a couple of hours passed before we all returned to the main dining room for dinner. Conversation was very happy and lively that evening with much joking and suggestions for future explorations. Kayla was her usual quiet self though obviously contented.

Kayla, Vincent and Maria built more of the legged vehicles, modifying and improving them over some weeks. I don't know who first called them horses, but the name stuck, despite the fact that they looked more like giant insects and the driver sat inside the body instead of riding on the back. So now, in a bizarre way, we had the horses I'd often wished for, though made of plastic and some metal, instead of flesh and blood... and hardly resembling the original animals at all.

The horses changed everything for us, having a major effect on our scavenging trips. They opened up lots of areas previously closed to us — most roads had been reclaimed by vegetation and the elements. Rising sea levels, failing drainage systems, and increased rainfall had turned many areas to swamp, but instead of being barriers, these now became preferred routes of travel as they tended to remain relatively open. The horses had no problem wading through them. Later models were completely waterproofed and able to swim across even deep water.

Soon after the first horses, Kayla and Gabriel watched some old videos in which people remotely operated small, robotic, flying quadcopter drones that sent back video to the operators. At Gabriel's request, Kayla made one, as a toy for him.

Jill watched him playing with it in Temperate-1 for a while and got an idea. She asked if she could borrow it to check on the nest of a parrot family in the Rainforest dome. At dinner that night, when Jill was talking about how she'd checked on the parrot nestlings with the aid of Gabriel's drone, Maria suggested the flying drone would also be a much quicker way to inspect the outside and inside of the domes for any maintenance needed. The much slower spider-bots could then be dispatched to do the actual work. And then Ben realised flying drones would make scavenging much more efficient and safer. They could fly ahead of the vehicles and check out the safest routes.

Kayla made extra drones with improved video and maneuverability for each of these purposes. They worked well for all these applications except for reconnaissance during scavenge trips. In that task they had a major limitation: lack of range. They had to remain light to stay aloft and although supercapacitors were much lighter than batteries they couldn't power the propeller motors for as long before needing to be recharged.

Vincent built a recharging platform on the horses to make recharging easier, and because supercapacitors could be recharged in seconds, instead of the hours that batteries would take, they would quickly be up and flying again, but it bugged Kayla that there didn't seem to be any way to extend the distance they could fly, before requiring recharge.

She remained frustrated by this until some months later Gabriel showed her an amazing TED talk video he'd found on a scavenged hard drive. The talk was by someone named Markus Fischer way back in 2011, and was titled "A robot that flies like a bird". (If you want to see this remarkable talk and demonstration, it is at https://www.ted.com/talks/a_robot_that_flies_like_a_bird.) Kayla immediately realised this was the solution to the range limitation. Instead of helicopter propellers she gave the drones wings that flapped like a bird's. This meant that they could take advantage of winds and updrafts to glide for long distances, using very little energy. Of course, hovering then became extremely difficult, but they could still circle over a target. She also used a hydrogen balloon as part of the drone's body to offset some of the weight — not to completely neutralise the weight, but to considerably lessen it, extending the range still further.

The next big change came, again, from Kayla. It actually began some months after the first drones, when she found out about the artificial intelligence (AI) which my Mum had been working on, but had never been able to complete. That became Kayla's main project and consumed almost all her time. Mum had intended to integrate it into the Habitat so it could take over the many functions that were currently controlled by separate systems which needed to be checked by people. Kayla would sometimes work for days on some problematic aspect of the AI. Gabriel spent increasing amounts of time with her, listening to her while she talked through the problems. We doubted he understood much, but he liked it. Vincent couldn't follow a lot of what she was doing. I sometimes had an idea of what she was working on, but more often she lost me too.

Then, using a combination of my Mum's notes, and information from the computer's library, supplemented with data scavenged from the Sunshine Coast University and the universities in Brisbane, Kayla managed to finish my Mum's AI project and fully integrate it into the Habitat's computer systems. She emphasised that it wasn't a conscious AI. It was not like a human mind; it was more like our cerebellum, the little hindbrain that we delegate tasks to, like the complex coordination of balance and muscle control required for walking. The cerebellum operates unconsciously so as to free our conscious mind — our cerebrum, the giant main part of our brain — for things that require attention. This AI could learn and control complicated procedures. It could even speak, but it didn't have presence or emotions.

Her completion of Mum's AI came about a year after she'd built the bird-like drones. The AI made the drones far more useful and much easier to operate. Instead of needing a person to control just one drone, the AI was able to direct several at once to scout out ahead of our scavenging journeys. Using our vehicle radios to relay the AI's control of the drones, as well as images, altitude, compass, and other data back to the AI, made our searches far more efficient — we explored many more places much more thoroughly, while taking far less time to do so. Additionally, the AI catalogued what it saw and could tell us what could still be found at places we'd previously visited. We could never bring back everything, so inevitably things were left behind that would sometimes be needed later.

At one of our evening meal meetings, soon after Kayla had made these new drones, Vikki had raised the question of adding more medical equipment, especially dental tools, as the Habitat's dental equipment had proven inadequate to deal properly with some recent problems. So we decided that the next morning Vikki, Ben, Maria, and I would take the new, improved drones on a field test, scavenging in some of the coastal towns that we'd been unable to reach with wheeled vehicles. The horses made it possible to traverse choked and broken roads and to enter areas that had returned to swamp, and although we'd used the horses in these areas before, we hadn't done so with the assistance of drones, let alone the winged, bird-like ones directed by the AI. We expected they'd make the job quicker and more efficient and let us cover much more ground in far more detail. It didn't quite work out that way.

We left at dawn in four horses. They're slower than wheeled vehicles on intact roads, and by mid-morning we reached the top of the range at Mapleton. At that point it was obvious a storm was blowing in from the ocean. We debated whether to continue, and decided that we'd turn back if the wind started to rise much. The sky darkened as we continued eastward, so that by about midday, when we reached the coast, light had fallen to something resembling deepening twilight. There was no rain, at least where we were. Lightning high above the clouds had initially lit that dark blanket only intermittently, but was now flickering very frequently, lighting our way eerily. Unfortunately it interfered badly with the radio control of the drones. The constant crackle corrupted the messages sent to them, and they would sometimes fly off in the wrong direction, not "hearing" the commands to return until a break in the lightning.

The final straw was when we were exploring near Coolum. One of the drones flew off to scout the way ahead. The sky flashed and flickered constantly, accompanied by continuous background crash, roar and rumble of rolling thunder. We watched helplessly as the drone, flying high, just kept on going. Ben, of course, raced recklessly after it. We hurried our horses to follow, trying to keep both Ben and the drone in sight through all the trees. I alternately yelled at and pleaded with Ben to slow down, but communications were completely obliterated by the constant crackling of the radio. (Maria and Vikki later told me they'd also been fruitlessly yelling at Ben to stop.) I was terrified of us becoming separated in this tangled maze of a forest and swamp in what had once been a housing estate, now overgrown with trees sprouting from what had once been gardens and lawns and roadside verges.

The forests which grew from fields and parks had an open understory, shaded by the canopy above so that few things grew below, making it easy to move through. The most difficult places were at the edges of open water, and the sides of unbroken road, and where buildings blocked growth. These allowed light to reach near ground level where the tangle of plants formed a nearly impenetrable barrier. This was both a blessing and a curse. The intact roads and the flooded areas let us see the sky and visually track the drone, but where the road was broken, and higher, dry ground allowed trees to grow, progress became difficult or impossible. It was worsened by the many roads that simply ended in a cul de sac. It was like a monstrous maze. I'm not sure if this would have been easier or worse if it had entirely returned to swamp.

Eventually, almost out of power, the drone glided in a slow spiral downward, to land somewhere out of sight. It took us a very stressful hour before we finally located the drone. I had visions of it crash-landing in a tree or on one of the broken houses, but it had miraculously landed neatly in the center of a round turning-area at the end of a dry, intact, dead-end street. Ben was the first on the scene. While his horse was still in the act of folding its legs, camel-like, to slowly settle its belly on the ground, he impatiently lifted his horse's canopy, jumped out, picked up the drone, and attached it to the charging rack on his horse. As he was getting back into his horse and was about to pull his canopy down again, Maria lifted her own canopy and was screaming something at Ben. Vikki and I lifted our own canopies to hear her. Muffled as she was by her mask, we could barely hear her over the constant rumble and crack of thunder. It took several attempts to make out that she was saying we should all return home (though her phrasing was a little more colorful). We all agreed. The lightning made the radios useless. It was too dangerous to continue exploring being unable to communicate properly, and none of us liked the prospect of losing one of Kayla's valuable drones or becoming separated.

When the lightning lessened somewhat, allowing us to communicate again, Maria, Vikki and I angrily unloaded on Ben, telling him off for his risky behavior. We could replace a drone, but couldn't replace him. Ben apologised, but I knew he was just placating us, so I pointed out that his impulsiveness and impatience had put the rest of us in danger having to follow him faster than was safe, in order to avoid becoming separated. He was silent for a little while and then apologised for real. He didn't mind putting himself at risk, but he would never knowingly endanger anybody else.

But the day wasn't a complete loss. We'd made more annotations to our maps — swamp intrusions, broken roads, intact buildings, and so on. And before the wild drone chase we'd found a dental surgery and salvaged a lot of its equipment and medications, and located a couple of medical clinics with things we could use.

After that incident Maria and Vincent improved our communications to make them more reliable in the face of the increasingly common lightning storms. They added computers to the radios for so-called "packet radio", in which speech was turned into data which, along with data from the AI, drones, and horses, was sent back and forth in tiny "packets" of information with checksums and error-correcting codes, similar to how the old internet sent and received information. Our improved communications used massive redundancy, repeating each packet ten or more times. Maria and Vincent also added optical communications in the form of bright LED lights, both visible and infrared (infrared had greater range through smoke and fog). Optics could only be used in line of sight, but it was nevertheless a useful extra backup system. And we got loudspeakers and microphones on the outside of the horses as a further safety backup. All this gave us clear and reliable communications no matter what the weather was. Maria also had the idea of giving each horse a radio locator beacon so that nobody ever again risked being lost if they became separated from the others.

Kayla kept making more drones with additional capabilities — arms to carry objects, legs to land on, and cutters to give access to overgrown buildings, lights to illuminate, radar to search for metal, and various other tools. No matter how many drones we added, the AI learned to control them all simultaneously. After a while, each exploration was accompanied by a flock of about twenty drones that would continuously take off from, and return to a rack on top of a horse, where they would briefly recharge. They would fly out to investigate any likely building in a broad path ahead, and when anything promising was found, the drivers would divert their horses to reap the bounty. Often we didn't even need to step outside our horses. The drones would do it all, under direction of the AI. We were mostly required for making decisions, for moving heavy items, and for complicated tasks, like opening doors. The early winged drones were not able to easily maneuver indoors so we had to do that on foot. Later drones, with their hydrogen-filled balloon-bodies were more buoyant, lessening the energy cost of flying so they could fly for much longer distances. They were still heavier than air, but the buoyant bodies let them fly more slowly if needed, allowing them the maneuverability now to negotiate indoor spaces.

During these expeditions, a couple of drones would remain high in the sky like little blimps, held aloft by much larger hydrogen balloons. They would only flap their wings when absolutely needed, and were tethered to their horse by a thin wire, through which they could communicate, without the need for radio. They were also continuously recharged via their wire. Those tethered drones were equipped with strange lenses which Gabriel had suggested, based on what he'd read about the eyes of a hawk. They could see a wide, panoramic view, but the middle of their view was highly distorted like an extreme telephoto lens. This let the AI see the wider landscape, but at the same time, watch closeup detail on the ground from way up high... like a hawk watching mice from a great height. When Gabriel explained it to me it reminded me of that amazing Escher drawing, "Balcony", which magnifies the center of view.

(A larger version can be seen at https://i.pinimg.com/originals/10/7a/75/107a751d65d634260de5db08c2f9af58.jpg.)

When I showed him a reproduction of the drawing on my tablet, he was delighted, "Wow! This is wonderful. But the eyes of the high drones are more extreme than this. It would be like one leaf on the plant in the balcony taking up a lot of the center of the image while the edges remained the same as they are in this picture. And right in the middle, you'd be able to see the smallest leaf veins."

I shook my head, "How does the AI make any sense of such a distorted view?"

"It doesn't look distorted to it. It just interprets what it sees. I think our eyes distort in a similar fashion, though not that much of course. In the middle we see heaps of detail, but the edges only see overall shapes. And of course, everything we see is upside down."

I shook my head again, "Huh?"

"The image which your eye's lens projects onto the back of your eye is upside down."

I remembered my basic optics. "Oh, of course... and reversed left to right."

Gabriel nodded, "At the end of the 1800s a researcher named Stratton experimented with wearing special glasses that re-inverted the image, turning everything right way up on his eyes' retinas. He had great difficulty moving around for some days, but after about a week, he became used to it and everything felt normal to him again. Then he took the glasses off and everything looked upside down to him again. Much later, in 1950, an Austrian, Theodor Erismann, repeated the experiment, though only flipping up-down, not changing left-right, and made a short documentary film of it, which overshadowed Stratton's detailed, much earlier account. Anyway, my point is, we adapt to whatever visual input we receive. Kayla's AI does the same when seeing through the drone's eyes."

(You can read more about Stratton at https://en.wikipedia.org/wiki/George_M._Stratton and Erismann at http://www.awz.uni-wuerzburg.de/en/archive/video-photo-archive/theodor-erismann/. Some of Erismann's video can be seen in http://www.youtube.com/watch?v=jKUVpBJalNQ. Some of Stratton's writings can be read at https://archive.org/details/psychologicalrev04ameruoft/page/n0.)

At the time, I'd stood, with a frowning smile, marvelling over this. Gabriel probably thought I was pondering the way the brain adapted to its senses, but I was actually amazed at the knowledge this young kid was absorbing from the Habitat's library and from conversations with Kayla and others. At that point he was, I think, only about six years old.

Even Dahlia and Matt, the unassuming, mildly religious couple who'd become the Habitat's main gardeners came up with some great improvements. Awful hailstorms and strong winds were occurring more often and had damaged many solar panels. During dinner at the height of a series of such storms, Dahlia said, "Matt and I have been thinking... couldn't the damage to the solar panels be reduced, or maybe even eliminated by imitating nature? Instead of large, rigid panels, couldn't we have hundreds of small, lightweight panels that were on flexible stems? Then they would bend with the storm..."

"Like in the fable of the oak tree and the reeds," Matt added. (Read the fable at Project Gutenberg http://www.gutenberg.org/files/19994/19994-h/19994-h.htm#Page_32.)

Dahlia continued, "...and during hail the hundreds of small panels would simply get knocked aside instead of getting cracked. I imagine them looking something like trees with the 'leaves' being solar panels. The trees would bend instead of risking being torn from their mountings like our existing panel assemblies. The 'leaves' don't need to point in just one direction, because the clouds diffuse the light so it comes from every direction anyway."

Vincent said, "I like it. Since so many panels have been damaged we need to find a way to make our own solar panels anyway. We can't just keep relying on scavenging them. I've already begun experimenting with replicating Ovshinski's amorphous solar cells. It seems to be a relatively simple manufacturing process." He looked at Kayla, inviting a response from her.

(Read about Ovshinsky: https://en.wikipedia.org/wiki/Stanford_R._Ovshinsky and his patent for easily manufacturing amorphous silicon solar cells: https://patents.google.com/patent/US4410558A/en.)

She glanced up at him, gave a single nod of her head, then, looking down again at the plate before her, said slowly, in her characteristically soft voice, "I've become interested in quantum dots and quantum wells. Initially, I was trying to make exactly tuned light sources... but I've also started to wonder if they might be used in reverse, as a very efficient way to capture light energy." (She didn't mention why she wanted those light sources. We found that out much later.) "For quantum dots and wells it's the nano-scale shape that's important rather than the material. By tuning the size of the nanoscale rods or cavities you could make them resonant to whatever frequency of light you want. After all, light is just an electromagnetic wave, like radio. These would really be tiny aerials. Silicon solar cells can only use a narrow spectrum of light because of the electron energy gap in the semiconductor. Lower frequencies don't have enough energy to boost the electrons over the gap, and higher energies waste the excess as heat, lessening their efficiency still further."

(Read about quantum dots: https://en.wikipedia.org/wiki/Quantum_dot and quantum wells: https://en.wikipedia.org/wiki/Quantum_well.)

Everybody looked back to Vincent. He raised his eyebrows and said, "Interesting," then fell silent too, brow furrowed in thought.

There was expectant quiet for a few moments, as everyone looked at Kayla and Vincent and back again, and when nothing more was said, there was general laughter. Vincent smiled. Kayla blinked in surprise. Gabriel was, as always, seated next to Kayla and leaned sideways to her, "I'll explain later."

Over the next few days Vincent built an example solar tree using existing crystalline solar cells, some of them cut from the hail-damaged panels. Several trials were required to ensure their stems were stiff enough to resist becoming tangled with each other, but flexible enough to yield to the windstorms and hailstorms, which continued to be unsettlingly frequent, giving plenty of opportunity for tests. Some of the small leaf panels still became damaged by hailstones, but on the whole they survived much better than the large, flat panels. And damage to a few small leaves hardly affected the output from a whole solar tree, whereas a damaged part of a large panel significantly lessened output from the whole panel.

He also built a small-scale process for making amorphous cells the way Ovshinski did. It worked well, and allowed the small panels to be cut out of the sheets in any shape desired, resulting in much more resilient solar cell "leaves", but soon after he'd done so, Kayla brought to the dinner meeting a working example of the quantum well solar cell idea she'd mentioned. It was a matte black flake about the size of a thumbnail. She put it on the table in front of Vincent, then she sat in her customary seat.

She said, almost as if talking to herself, "That's much more efficient than the standard crystalline or amorphous silicon solar cells. I made it out of carbon... mostly. They can be tuned to pick up all the light from infrared to ultraviolet, giving very high efficiency... especially when converting ultraviolet, which has the highest energy."

Gabriel said, "Cool!"

Holding it on his fingertip, and peering at it, Vincent agreed. "Very cool."

Vincent abandoned his amorphous solar cell production and devoted his time to working out how to make large amounts of Kayla's solar cells. Over several months, he and Maria created a forest of solar trees using the new solar cells. After some successful experiments outside in the weather, they went ahead and replaced all the old panels around the Habitat with the new artificial trees. Kayla had also added a special transparent surface to the solar leaves similar to that which waterlily pads have, making them self-cleaning — she referred to it as the lotus-effect. (Read about the lotus effect on Wikipedia: https://en.wikipedia.org/wiki/Lotus_effect.)

The night that the last of the solar trees were intalled and switched on, everybody toasted Dahlia and Matt. We had more electricity than ever, and it was now very safe from violent weather.

Several months after that, we found out why Kayla had been interested in tunable light sources. At a dinner meeting Gabriel said, "Kayla and I have been running an experiment outside, which is finally ready. We'd like everybody to meet us outside the entrance to the Habitat tomorrow, at eight in the morning, so we can show it to you."

Blossom asked, "What experiment, honey?"

That surprised me a bit. Blossom usually knew what the kids were doing way before anybody else.

Gabriel said, "We'll show everybody tomorrow. It's much better to show it than to try to explain it. Describing it doesn't really convey the experience." That made us all very curious, but no matter how we asked, they wouldn't elaborate, saying only that we'd see in the morning.

The next morning at eight, dressed in our protective clothing and hats and masks, all of us except for Cliff, were standing outside the Habitat's entry tunnel. Gabriel asked, "Is Cliff coming?" His radio voice was tinny in our ears.

His mother, Vikki, said, "He should be along soon. He was just finishing up a few things in the biology lab."

"I'm almost there," Cliff's voice was clear, but not as strong in our earplugs. "I'm in the garage and putting on the last of my protective gear so I can head on up the tunnel to join you all."

We waited, standing in the already oppressive heat, under the overcast sky. There was hardly any conversation, despite the intense curiosity we all felt. A few minutes later Cliff walked out of the tunnel and waved to us. "Sorry."

Gabriel motioned for us all to follow Kayla. She led us to a broad, fairly fresh mound of earth, about three meters high at its top. It had been washed out to maybe a hundred meters across its base. A scattering of sprouting vegetation was trying to resist erosion by the frequent storms. A gouged out section in its side sheltered a door. Kayla opened it and we all followed her in. Gabriel closed the door behind us. Inside, a dimly-lit corridor veered to the right descending in a spiral. There were no steps, just a smooth floor. The walls and ceiling were a single smooth curve arching over our heads, and where the floor met the walls there was no edge either — they merged in a continuous surface, almost shiny, white. Above us the surface glowed coldly. As we descended, I could put my palms on the walls on both sides without fully straightening my arms. Two people could walk, uncomfortably, side-by-side; three couldn't.

Jill asked, "How far does this go?"

Gabriel said, "Not much further. It takes us down about twelve meters below ground level."

Ben said, "That's like four storeys."

Maria held Vincent's elbow to steady him. He was becoming increasingly frail these days and the smooth, sloping surface was strange to walk on.

Presently we came to a little room at the bottom. Kayla opened the door there, letting strong daylight spill into the small room, and she went through. Gabriel followed, beckoning us too.

We stepped through into an amazing, large, very brightly lit, domed chamber, our footsteps echoing on the hard floor. Gabriel and Kayla had removed their masks and goggles, so we did likewise. The air was cool in here.

Gabriel said, "We ran an oxygen concentrator for about a week." He pointed up, "The ceiling is nine meters high at the middle," then pointed to the far side, "and eighteen meters across. Unlike the Habitat environments it's only half a sphere. We could have made it a full sphere, but that's actually more complicated. I know it feels very big, but that's just because it's empty. It's really only about as big as the garage. We don't think there's any reason we couldn't make places the size of the Habitat's environments. Maybe even larger."

Vincent was standing at the wall by the door we'd just come through. He was touching it with his fingers and peering at it. "How is this lit? The surface seems to glow."

Kayla spoke now for the first time this morning, "Remember I said I was looking into using quantum dots to make tunable light sources?" She raised her arm to indicate the dome interior with a wave.

Vincent smiled, "So you've embedded millions of microscopic red, green, and blue light emitters in the dome surface."

She shook her head, "No, they're randomly tuned to frequencies within the entire spectrum of light that the sky allowed through from the sun before the catastrophe. And they aren't actually embedded; they're part of the surface itself, by the same process that lays down the final several layers."

Dahlia had her face upturned to the ceiling, eyes closed, and hands held out, "It feels warm."

"Yes, it produces some infrared and ultraviolet too. What you feel as warmth is mostly ultraviolet generating heat in your skin. I decided, for safety's sake, to concentrate most of the ultraviolet light emission at the very top of the dome. That keeps it away from your eyes — eveybody should avoid looking directly up. Incidentally, plants should do very well under this light. We haven't tried them yet, though."

Gabriel said, "Funny story on the topic of ultraviolet light: the first time Kayla and I visited this room she remarked how different I looked under this light, but she looked exactly the same to me. I became curious. After a few tests I was satisfied that Kayla sees UV light (ultraviolet light, that is)."

Everybody looked at Kayla with surprise. I don't know what we expected to see in her. She still looked the same, of course.

Gabriel continued, "This isn't as odd as you might think. There are two kinds of light detecting cells in the eye: rods and cones. The cones are the ones that respond to color, but they need fairly high levels of light. The rods are sensitive to low light levels. Most animals — birds, reptiles, frogs, fish — see four primary colors: red, green, blue, and ultraviolet. But our little, burrowing, rat-like, mammal ancestors who survived the asteroid impact that killed off most of the dinosaurs were nocturnal — they were color blind. They probably retained a few color receptors though, which, at the time, were essentially useless. As mammals spread into daytime ecological niches left open by the devastation of most life, color vision became useful again and those animals that had more color detectors in their eyes survived better. Most mammals regained only one or two colors. Primates — monkeys and apes — regained three. We are apes. I've read records that some people could see the fourth color — ultraviolet. They were all female."

Blossom asked Kayla, "What does it look like?"

The corners of Kayla's mouth twitched upward briefly and she said, softly. "Can you describe to me what yellow looks like?" She shrugged. "I thought everybody saw colors the way I do. It was only in here, where the UV light is much stronger and everything looks so different that it was worth even commenting on. The thick clouds filter out most of the UV light outside, and all the LED lights and computer screens are red-green-blue lights, so UV is missing there too." Kayla flicked a glance at the rest of us. "Does anybody else see the light in here as a very different color?"

We all looked around at each other. Nobody spoke up. Kayla sighed, disappointed.

Maria changed the subject, "How are the lights powered? It must require a lot of energy to produce this amount of light."

Kayla turned to Maria, relieved that she was no longer the topic of conversation, "Well, yes, and no. The quantum dots are very close to 100% efficient and the electricity comes mostly from a whole lot of extra solar trees we added above."

Gabriel said, "We also took some of the Habitat's surplus electricity."

Awed, I asked, "How on Earth did you kids dig this... this..." I was lost for words and gestured around at the enormous domed space, "all this?"

Kayla pulled something out of her jacket pocket and held her hand out, flat, for me to see. We all gathered around to look at it. It resembled a large black ant, a bit bigger than the bull ants that used to live before the catastrophe. It was the length of the last two segments of her index finger, and had long legs, and large jaws, reminiscent again of a bull ant. But instead of scurrying anywhere it simply stood, motionless, on her hand. (Read about bull ants at https://australianmuseum.net.au/bull-ants.)

Gabriel said, "Kayla and I made hundreds of these little ant-bots, then put them outside, about fifty meters away from the Habitat's vehicle entrance. They have a pretty simple high-level program to remove grains of soil and deposit them some distance away. But Kayla wrote it so that they concentrated their digging vertically at one location until they reached a depth of about three meters. Then they should switch to--"

Blossom softly interrupted, "To the point, Gabe."

He nodded. "We programmed them to dig this. They work day and night, without stopping, so it took less time than you'd think — just a few months. The final thing they dug was the entry spiral over to the side. Kayla and I added the door at the top and the door at the bottom by hand."

I felt the wall with my hand. "But this isn't just dirt or even rock. This has a smooth, hard finish, and you said the light emitters are part of it..."

Kayla said, "That's a series of layers that reinforce it so it won't collapse, and also makes it airtight and waterproof."

Vincent was puzzled. "How?"

Kayla turned to Gabriel for him to answer. He said, "I read in the library how snails and shellfish slowly build up their shells out of microscopic layers of calcium carbonate interleaved with protein. We did something similar to secrete many layers as a composite that's stronger than concrete, using only room-temperature chemistry, like they do... snails and shellfish, that is."

I leaned forward and squinted at the little robot on Kayla's hand, wishing I had my glasses on. "How does it secrete the shell?"

Gabriel shook his head, "No, not the antbots — Kayla helped me make some slugbots." He smiled, "We call them slugbots because they don't have legs, and they're wet, and move like slugs or snails, depositing the layer as they go. They're a few times the size of the antbots — about as long as your hand, but about as wide as two fingers. Both kinds of robot are completely automated. You just program where you want a room, and over a few months hundreds of them just excavate and seal it."

Vincent asked Kayla, "How did you make such a tiny robot? We don't have the tools to make things in such... small detail."

She said, "I made tools to make smaller tools, then used them to make even smaller tools. When working on a very small scale you have to use different methods though. You can't use screws or rivets or solder or welding when things are small. And it's easier to accumulate shapes than to carve them from something bigger. Designing things to self-assemble, where possible, is best."

I asked her, "What did you make it out of? It looks like shiny, black metal."

"Mostly polymers — plastics. I had to pick my materials very carefully. Metals are almost useless because they're chemically unstable and too difficult to shape. Structurally, polymers, gels, and low temperature ceramics work best. I used tensegrity quite a lot."

Tensegrity. I'd heard of the term many years ago, but couldn't remember what it was. I pulled my handheld computer out of my pocket, hoping its wireless could reach the Habitat computer from here, so I could search for the word, but there was no signal.

Kayla noticed what I was doing. "The electrics in the dome that supply the light act like a Faraday Cage. Wifi can't get in or out."

"Uh... I was just looking up 'tensegrity'. I've heard of it before, but can't remember."

"It's just a way to build strong, flexible structures by balancing tensile and rigid parts. It's often made out of rods and cords. Living systems use it a lot."

I smiled and thanked her. Now I remembered where I'd read of the term, ages ago. It was in connection with animating computer models of living things. I looked at the kids' robotic ant with new appreciation.

(Read about tensegrity: https://en.wikipedia.org/wiki/Tensegrity and Faraday cages: https://en.wikipedia.org/wiki/Faraday_cage.)

Vincent frowned, "How the hell did you get something that small to move reliably?"

Kayla said, "It wasn't easy. A lot of the usual mechanical systems don't work well at small scales. Standard hydraulics, pneumatics, wheels, and pistons are all pretty useless. They lose too much energy fighting friction and electrostatic attraction. Things that bend and stretch with fibers and rigid levers work better. In small things chemical energy works better than supercapacitors or batteries, so we feed them."

Maria was astounded. "You feed them?"

Gabriel laughed. "Yes. We use sugar dissolved in water. It's stable, easy to grow, and breaks down to produce lots of energy. It's no accident the natural world uses it so much."

Matt snapped his fingers, "Ah. That's why you wanted us to plant those sugar beets."

Gabriel smiled. "We've been extracting and refining the sugar in the chem lab. It's not fast enough though. In the future we'll do better. In the meantime we've had to use sacks of sugar from warehouse scavenging."

Maria asked, "When you dissolve the sugar in water, doesn't the water interfere with their mechanics and electronics?"

Gabriel said, "No, their internals need water for gels and to support the reaction breaking the sugar down. The antbots don't need much water, but the slugbots need heaps."

Vincent understood, "Ahh, they lose it in secreting the reinforcing." He patted the wall.

Gabriel nodded.

Jill asked, "So... was there any other reason why you brought us all here? — Apart from wanting us to see this amazing place."

Gabriel said, "We want to get permission to connect it with the Habitat."

Everybody looked at Jill and me. After a little while, I spoke, "Well that's the logical thing to do, I guess. The biggest problem, of course, is that it's contaminated... so the only places it could be connected to are the entry tunnel, or the garage... unless it could be decontaminated — and I have no idea how you'd do that."

Cliff had been silent all this time. He raised his hand and said, "Ummm... I think I might have a way to do that."

Jill said, "But even if this place can be sterilised satisfactorily, I don't see how you can dig through the Habitat's steel-reinforced concrete."

Gabriel smiled, "You'd be surprised what Kayla's little antbots can do." He waved his arm to indicate the large space, "This wasn't just dirt. They had to cut through layers of rock and large boulders that had to be broken down and removed."

Jill persisted, "But steel rebar?"

Gabriel said, "I think they could...." He looked at Kayla, who nodded.

They were right; the antbots were, astonishingly, able to cut their way through not only the concrete, but also the steel reinforcing. I think the antbots were using some kind of corrosive substance as an aid. It took them a few months to do so, but they eventually cut through, connecting the new underground room to the entry tunnel.

The method Cliff used to get rid of the alge in the new room was surprisingly low-tech. He brought over a hand-pumped, back-pack pressure-spray, of the kind bushfire fighters used before the catastrophe. This was used to wet down all the interior of the room with water which contained a small amount of nitrate and phosphate so as to trigger any algal spores to start growing. The spores are more hardy — more difficult to kill — than the growing algae. To reach the high center of the dome we had to assemble and stand on a tall, worryingly ricketty, makeshift scaffold. Some of the water that dripped from the ceiling and ran down the sloped sides to the perimeter was swept up with a broom and added to a large, glass, kitchen mixing bowl containing clean nutrient water which he left sitting on the middle of the floor. A day after that, Kayla turned the lighting off in the room, and it was sealed up, dark, for a couple of weeks. Any growing rogue algae couldn't survive without light. At the end of that period the lighting was turned on again for several days without entering the room so that it remained isolated, but now with any algae that might have survived, growing again. Then Cliff entered the room, took a sample of the water in the bowl, and checked it for the rogue algae. There were none... at least none of the rogue species, only a few other, more hardy species.

Later, Cliff improved his procedure by strongly irradiating any newly created room with UV-C light for a couple of days, following the dark period, to kill off even the more resistant algae. That was because he'd read about horizontal gene transfer between bacteria and other species and was worried about the risk of allowing another, more hardy rogue species in. (Read about horizontal gene transfer: https://en.wikipedia.org/wiki/Horizontal_gene_transfer.)

Kayla's machines continued to produce great armies of the little robots which dug more, and bigger, underground spaces. We never needed to decontaminate a space again because when a room had been excavated and sealed off, the slugbots laid down a layer that produced high intensity Extreme ultraviolet light. The new space would be subjected to alternating periods of a week of high UV, then a week of darkness. After cycling this a few times the space passed our tests for rogue algae. The slugbots would finally lay down a layer producing ordinary, harmless light. Each new space was then linked with the others and the main Habitat, though no others were linked with that first underground dome because of its tainted connection to the garage's entry tunnel. It became a kind of second garage — a temporary storage place for things brought back from scavenging trips. It lessened the burden of clutter on the garage.

* * *

part 11 - bang

Month by month, year by year, the storms continued to worsen. As the cloud cover deepened we added more and more solar trees to provide power for the Habitat. We were initially reluctant to clear too many trees away from around the Habitat as they deflected much of the ferocity of the storms, but we really needed the space for more power. Vincent tried windmills, but they were not much help. They were either becalmed on normal days, or had to be feathered (turned away from the wind) during the storms. This was not a good place for standard wind-power.

The increasing intensity of the storms also meant we had to be more careful in our scavenging trips. Vincent, Maria, and Kayla made some protective changes to the horses. The long, mechanical legs now folded up in a way that flattened the horse profile. When crouched like that the feet could drive powerful clawlike hooks into the ground to firmly anchor the machine in place. Lastly, when the drones were moved into the luggage compartment from their charging rack, a padded, carbon fiber armor — light, yet incredibly strong — hinged at the sides, could unfold from under the rear to cover the entire horse like the hood of a baby's pram. This protected it from flying debris. It allowed us, if caught outside during a very bad storm, to simply hunker down and ride it out. The armor covered the solar panels, but there wasn't much light in heavy storms anyway.

One morning a howling windstorm grew and grew. Trees outside the Habitat were whipping violently, and the color of the light through the dark clouds slowly changed to a weird greenish glow. Jill and I were milking the goats in Savanna-2, when suddenly, wave after deafening wave of large hailstones came crashing almost horizontally against the dome, making the goats very nervous and skittish, and difficult to manage. We could barely hear each other's shouts over the assault. It reminded me of some movies we'd seen where people were near the roar of a jet engine. It was very unsettling and uncomfortable. I couldn't imagine anything louder until an earsplitting explosive boom made us and the goats all jump. We looked up to see a large tree had been uprooted and blown against the side of the dome. Hurriedly we gathered the goats and led them to the door into Savanna-1. They were so spooked we had to turn off the airlock's air jets or we would never have got them through. Then we sealed off Savanna-2, because it was difficult to believe that the dome hadn't been damaged by the tree. Either the wind was abating or the lesser exposure of Savanna-1 to the wind from the west let us hear each other's shouts slightly better here.

Jill yelled, "I'll stay with the goats in case this dome is hit too! You get back to the others and tell them what's happened!"

I pointed to the ground beneath our feet, "Get them below into the storage rooms! They'll be safer and calmer down there!" then I ran all the way to the house in Temperate-1 to tell the others.

Only Maria, Dahlia, and Matt were there. The relative quiet inside the living room, made it a great relief to be able to talk normally. "Where is everybody?" I gasped and panted from the run.

Matt and Dahlia looked blank, and Maria said, "Dad and Ben are in the big engineering lab below. Why? What's happened?" She was looking worried.

Rather than explain just now, I put up my hand and ran across the room to the intercom. I selected the appropriate connection, and pressed the button rapidly several times to beep at the other end in what I hoped was an urgent-sounding fashion. A few seconds later Vincent answered it, "What's up?"

Between puffs and pants I said, "We have an emergency. Possible dome breach in Savanna-2. Need to work out what to do, quickly as possible. Jill's with the goats in Savanna-1."

Luckily, it turned out that nobody was outside the Habitat. Blossom and the kids were in the mouse playroom, and Cliff and his parents were in the medical labs.

Ben brought a couple of the old, small, quadcopter drones, which we still used for dome inspection because of their ability to hover. He ran to Temperate-2, then to the door of Savanna-2, where he released the drones into the air. He sealed the door and ran back to us in Temperate-1 where Vincent, out of breath from climbing stairs, had joined us in the living room. Everybody else had joined us too. We watched the screen while the AI helped us direct the drones so that we could examine the dome under the fallen tree-trunk. The AI also superimposed on the bottom right corner of the screen the numbers for the oxygen and carbon dioxide levels in Savanna-2.

Miraculously, the dome, though dented, was not cracked. But this served as a powerful warning to us. The storms had been getting more intense every year. They always had, but something in the atmosphere must have recently crossed some threshold, causing them to ramp up more rapidly in destructiveness.

Maria suggested that the antbots, when digging the new underground rooms, should deposit the excavated earth around and over the main Habitat, gradually burying it, and that Kayla should set some slugbots to work installing artificial lighting in the seven original domes. Everybody reluctantly agreed. We were unhappy to lose the sky. Even though it was always overcast and increasingly dangerous, it was nevertheless the vast outside. When we could no longer see the sky, then we would truly be inside, confined, cut off.

The earth mound, as it gradually grew around the Habitat, was populated with more solar trees to help power the light emitters in the domes.

As I mentioned earlier, we'd tried using windmills to generate power, but they'd either been almost idle or had to be turned away from the wind to protect them from its violence. Most had nevertheless been eventually destroyed by the storms. With the increase in frequency and severity of the storms Vincent and Maria had also been building a very sturdy vertical axis wind turbine to augment the energy from the solar trees. As the light was decreasing due to the thickening cloud cover and the winds were becoming more ferocious, it made sense to take advantage of that. After the turbine had been built and mounted and was contributing nicely to the Habitat's energy supply, Gabriel came up with a very simple idea: attaching the leaves of the solar trees with a piezoelectric material, so every time they waved or fluttered in the wind they generated electricity from that motion. We gradually replaced all the leaf and branch connections in the now hundreds of solar trees — a very, very tedious job — and their electricity output increased tremendously. Now the solar trees reaped energy from the wind as well as the increasingly dim sunlight. (Read about piezoelectricity here: https://en.wikipedia.org/wiki/Piezoelectricity.)

During the long, slow process of burying the Habitat domes, Kayla's slugbots added an illuminating surface as a ring that grew slowly from the low edges toward the high center of each dome. Instead of making the environments dimmer, it gradually lit them more brightly. Kayla had designed the artificial light to mimic the light of many decades ago, before the catastrophe, when the world saw blue skies and shining sun, instead of the permanently overcast, dull gloom.

Initially, as the domes began be to be buried, I experienced a strange mix of relief and claustrophobia. When I mentioned it to Jill, she agreed; she felt it too. But the feeling passed long before the domes were completely covered. The process was so slow that it took a few years, but eventually the antbots dug out enough earth to completely bury the entire Habitat and our encapsulated world was illuminated only by artificial light. Surprisingly, it turned out that the bright, interior "skies" made us all feel happier. We'd never realised how oppressive the perpetually dull skies were. It was like a weight had been lifted from us all. The animals and plants in the Habitat responded well to the increased light too, and became much more productive.

The antbots continued to add soil until the original Habitat domes were, at their highest points, under a few meters of earth. At that point the additional underground rooms they'd excavated had roughly quadrupled the cultivatable land for our plants and animals. They comprised two more truly enormous rainforest environments — much bigger than our existing one — joined as one by an enormous arch. We would have to wait twenty or thirty years for the seedling trees to mature. These environments are so wide that for safety's sake Kayla programmed the antbots to leave some columns to help support the roof. We also added another temperate environment, a much larger savanna one (also with columns), and a mixed environment with land and fresh water. For this latter experiment we made a little stream that began from a very large pool, flowed through the gently sloping hilly environment, and around a wide, meandering circle to another pond next to, but lower than the starting pond. Then the water was slowly pumped back up the two meters to the higher starting pond from where it would run down through the creek again, simulating a permanent running water environment. It was a bit tricky getting the mixed ecology balanced, and we had to carefully select animals and plants from the aquatic and temperate environments.

The new environments had to be much lower than the existing ones. The tops of their domes had been buit to already be below the original gtound level, also their size meant the distance from the top of their domes to their internal ground "surface" was much greater. So the connecting passageways were via underground rooms from the old environments, except in the case of the lake and marine environments. They had inclined connections from above their "surface", in order to eliminate the risk of water leaks, so that walking from the lake environment to the Western part of newRainforest was like walking down a hill.

We populated the new spaces with animals and plants from our existing environments, but also added some carefully cleaned seeds of interesting grasses, as well as cuttings of shrubs and trees we'd been collecting in our scavenging trips. With the loss from the outer world of all bees, moths, beetles, bats, birds, and small mammals to pollinate them, much of the outside world's plant life was destined to die out. Only those plants that were pollinated by wind or water, or that spread by cloning would survive in the long term outside our Habitat. Already most of the annuals had gone extinct.

The goats seemed especially happy with all the additional space in their new savanna. But of course the antbots didn't stop digging at just those extra spaces; they kept going. Kayla said the only reason she might ever instruct the antbots to stop excavating more rooms is if somebody worked out a way to defeat the rogue algae.

One evening at our dinner-meeting Vikki asked for everybody to to listen to Dahlia, who had something to say. This was unusual, as Dahlia and Matt were both shy and rarely spoke out about anything. Everybody turned to Dahlia.

She looked very uncomfortable, twisting a napkin in her hand. Matt, sitting beside her, had a comforting hand on her shoulder. She said, "I'd been feeling ill a lot lately and asked Vikki to do a checkup on me." She paused for a moment, seemingly looking for the right words, then just let it out, "I'm going to have a baby."

There was surprised silence for a moment then cheering as many of us got up to hug Dahlia and shake Matt's hand. Matt looked embarrassed and pleased at the same time. Dinner that night became a celebration. This would be the first child born into the Habitat. (Jill and I were young children when her parents and mine first came to work here while the Habitat was being built.) This lucky child would have eleven doting extended family members in addition to her parents.

Nine months later, the baby girl was born. Dahlia and Matt named her Hope, which we all thought was very fitting. She made us feel differently about our place in the world. Gabriel spent a lot of time teaching her. He thought of her as his little sister, just as he thought of Kayla as his big sister.

* * *

part 12 - journeys

So, over the next few years we all settled into our roles in the expanding, but now completely underground, Habitat. Our oxygen concentrators let us explore further afield in our armored mechanical horses, accompanied by small flocks of our winged, bird-like drones controlled by the Habitat's AI, and the birth of Hope had uplifted us all, giving our little colony a future against the alien, hostile world outside.

One evening, while we were all watching a science fiction movie set on a ferociously hot planet, Jill sighed, "Oh, wouldn't it be nice to be able to move around outside in a cooled suit like that." A few of us murmured in agreement.

When another character in the movie wriggled into their suit via a hatch set into its back, with the suit attached to the outside of the building by that hatch, Blossom said, "Something like that could let us get into and out of them without having to go through decontamination, too." I paused the movie and we all looked at each other, astonished. What a wonderful idea!

We resumed watching the movie, but I noticed Vincent had switched his tablet computer on and was writing and drawing, and Kayla, who was sitting near him, was watching what he was doing rather than the movie.

The next morning I went to the large engineering workshop to talk with Vincent about the spacesuit idea, as I'd had some thoughts during the night. I found Vincent, Kayla, and Maria working on a prototype water-cooled suit. They'd sewed thin plastic water pipes onto a stretchy full-body garment which was currently being worn by a clothing-store mannequin. I smiled to myself; I'd been skeptical when Jill had salvaged that dummy on a scavenge trip an eternity ago.

Maria explained to me what they'd accomplished so far this morning. She indicated a tiny aquarium pump sitting on the bench next to the dummy, "This circulates the water in the tubes." Then, next to the water pump, she pointed to a small block, roughly a cube, about a handspan wide, tall, and deep. "This is the cooler. We tried a mechanical heat pump, but Dad doesn't think it would be reliable being bumped around, so we're trying a peltier device heat pump. It's not very efficient, but it has no moving parts to wear out and doesn't mind being treated roughly."

Vincent said, "They're also a lot lighter to carry around and noiseless. The inefficiency might be a problem, seeing as we want to use supercapacitors rather than batteries. Batteries store more, but are much heavier. Supercapacitors are far lighter and can recharge in seconds, but even the best designs don't really hold a lot."

Maria said, "Kayla thinks insulation from external heat is the key. Then we only have to cope with body heat buildup." I saw Kayla nod.

Vincent was using heat-conducting paste to attach a black aluminium heat sink to the flat peltier device (actually six devices) which together covered an area about the size of a hand. The heat sink had several fins projecting from its surface to help conduct heat away.

My idea had been about using water cooling tubes, but carrying a container of ice which, as it melted, kept the water cold, but I saw now that the ice would be far heaver and more awkward than the little Peltier heat pump, so I didn't bother mentioning it, though I'd also been thinking the pumping could be done by the person moving.

I said, "I know the little water pump probably doesn't use much electricity, but could you save that by pumping the water using the person's movements? For example breathing..."

Vincent paused to think. "Interesting idea. I guess we got trapped into thinking of an external pump because of this inanimate dummy." He smiled. "I can already see a couple of possible ways to use breathing to pump the water."

I wished them well and left them to it.

That evening at the dinner meeting they presented the prototype. It was actually two suits. Maria demonstrated, wearing a t-shirt, short pants, and socks. She first pulled on the stretchy, thin, fragile-looking undersuit with the tubing sewed into it. She fastened a wide belt-like strap around her chest under her breasts and smiled to me in acknowledgement, "This has to be firm. It runs the water pump from my breathing."

Ben and Matt held the rumpled, shiny, mirror-like, outer suit by two handles on its front. Maria said, "In the movie the astronauts got into their suits through the back, but we think access through the front will be better so we can operate the crucial seal with our hands." With the suit behind her, she squatted and leaned backwards a little, raising her arms into the suit, then stood, pushing her arms and head into the upper part of the suit. Finally she raised each leg and pushed it down and back into each leg of the suit. Matt and Ben had to lower the suit a bit because she couldn't get her feet high enough to go through the chest hole. The suit was fairly loose and let them do this.

Vincent said, "When this is on a wall we think it will be easier if we have some rungs on the outer wall that the person getting into the suit can pull themselves up with." He shook his head, "But I'm damned if I know how I'm going to manage these gymnastics."

Most of us chuckled.

Maria's face was hidden behind the reflective visor, which appeared to be a flat piece of plastic that had been curved around the face to give good horizontal visibility. She walked and skipped easily around the room, then back to Ben and Matt who grabbed the handles on the edges of the chest again. She came back out of it the same way she went in — pulling each leg up and out first, then squatting down to pull her head and arms out.

Carefully removing the delicate undersuit, she said, "The whole thing is really light — much lighter than the clothes we normally use outside, and will keep us nice and cool. We need to make it more sturdy — at the moment it's a bit fragile because we only have very thin mylar glued to a thin layer of foam. We need to find some thicker mylar, or work out how to make our own."

Kayla frowned and murmured, "Vacuum deposition of aluminium vapor on polyethylene sheet. Difficult. Or laminate to a thicker sheet..."

Maria continued, "And it would be nice to make it a little less loose, so that moving is easier. We're still working on the best way to attach it to the wall so that rogue algae can't get past when we separate and then later reconnect, but we have some ideas on that too. I think we're going to have to tailor-make each suit to fit the wearer."

In less than a week, we had a sleek liquid-cooled suit attached to an unused door into the garage. We could get into the suit from inside the habitat, seal up the entry and the suit, then detach to move about freely. Getting into and out of the suit had been made easier by making the opening much larger so we didn't need to be such contortionists. When the suit was detached from the wall, the front, no longer rigid, folded down small to fit the person properly. Of course we didn't need the suit to be pressurised or have all the bulky, rigid protections of the spacesuits in the movie. It was just a light, completely sealed suit that had cooling, air, and radio. Maria had been right, it was considerably lighter than the all-covering clothing, gloves, hat, mask, goggles, and equipment we normally sweltered inside. In tests we found that not only was it infinitely more comfortable, but it greatly reduced our water consumption too, because we didn't sweat so much. And as a bonus, we noticed that the comfort meant we didn't make as many mistakes and let us stay outside for longer without getting tired.

Over a few weeks we made one for each of us and added a separate attachment point for each suit in the wall beside the one already made.

Kayla, Vincent, and Maria modified the horses so that the suits could attach to each side of the cockpit, too. When the person had squirmed out of the suit into the horse, the empty suit would be mostly pulled inside-out, through its own belly, while still remaining attached to the outside of the horse. Then a strong external cover would slide shut over the opening, to protect it from the elements. Having two suit attachment points allowed a second person to enter the front of the horse to help the driver in an emergency.

The suits made long distance expeditions much easier, and we soon made journeys south to Brisbane and the Gold Coast, west to Roma, south-west to Toowoomba, and north as far as Gladstone.

On journeys south we were always on the lookout for the slavers, but we never encountered them, or anybody else, though on a few depressing occasions we did find the remains of people who must have eked out an existence for decades after the catastrophe. They must have died thinking they were the only people left in the world. That didn't bear thinking about too much, though such scenes would linger on in my memory, to occasionally replay in my imagination during quiet moments, making me cringe. I'd involuntarily feel what it must have been like for them. Horrifying. It made me forever grateful for the good luck Jill and I had in being being raised in the Habitat, and then, on top of that, finding this group of wonderful people to share it with.

At one of the evening meals Vincent told us about an old scavenged text he'd been reading, which described a very large data center in the outer, South-Western suburbs of Brisbane. He suggested it might be a good place for us to try to find. We'd had some successes before in plundering data centers. They often contained "mirrors" of huge repositories of software and other information. A mirror is what they called a copy of a distant site. In times before the catastrophe, mirrors decentralised data and made access faster and easier because people didn't have to clog up main data routes connecting to sites elsewhere in the world. It also saved a lot of money for the companies that provided people with internet connection. Vincent thought the size of the data center warranted investigation.

It had been months since we'd gone on a long scavenging journey so we spent the next couple of days organising supplies and checking equipment, then Vincent, Maria, Kayla, Ben, and I set out before daybreak in five horses with several birdbot drones scouting ahead.

Long journeys like this required us to be as independent as possible. The long times spent inside the horses meant they needed to have small composting toilets, and the distance from the Habitat and interference of lightning storms necessitated some intelligence in the horses to control the drones. Communication with the AI back at the Habitat had become a major difficulty, even with all the specialised encoding and redundancies that Vincent and Maria could apply to the problem. On this occasion though, the journey was uneventful. Surprisingly, the weather stayed calm and evenly overcast, without storms the entire journey, making it much less stressful.

We made good time. It took us about seven hours to reach the general area where the data center had been, but we spent another couple of hours trying to find the actual address. Most of the industrial parks here had become dense forest and the roads were so broken and festooned with shrubs and trees that making way through them became very slow and somewhat dangerous. We couldn't risk damaging any of the horses, so progress through the dense vegetation took much longer than we expected.

Eventually we located the featureless, gray, single-story front of the data center building. It had been built into a hill, perhaps as a climate control measure. We had to break our way in, as it was locked and sealed. Inside was dark, but amazing, pristine. Everything was dust-free, clean and shining under our torches, as if it had been running yesterday. I had the nagging feeling that we were trespassing, but of course, without power the last time anything had been operating had been many, many decades ago.

After about half an hour spent examining the equipment, punctuated from time to time by gasps of surprise from Maria and Vincent, we decided to take as many of the drives as we could fit into the horses' storage compartments, then come back for more on further trips until we had it all. Thankfully the drives were solid-state, which made them light and easy to carry.

It was dark outside by then, so we had to stay overnight and head back in the morning.

It took six journeys over a few weeks, between storms, to retrieve all the drives, and a few more months to get much of the associated equipment. Kayla felt we really only needed the drives, but Vincent had some idea about adding to the Habitat's computational resources. He explained it to us, but I didn't really understand. Kayla didn't agree with him on that, but helped anyway. She and Maria built several extra drone horses that would simply follow the others. Because they didn't need pilots, all the internal space could be used for storage. Gabe called them "pack mules" and the name stuck. Without them it might have taken most of a year to bring back all the equipment that Vincent wanted.

We had a whopping big, jaw-dropping surprise when we finally connected all the salvaged drives up to the Habitat's computers. They contained what seemed to be a complete copy of the Internet Archive project! This gave us access to most of the internet as it used to be — a vast repository of information almost without measure. As if that wasn't enough, they also included a full copy of Wikipedia, Project Gutenberg, Librivox, Sourceforge, iBiblio, Sci-Hub, LibGen and much more, right up to just before the catastrophe. There was even a partial mirror of YouTube. Our knowledge base had just leaped far beyond anything we could have ever imagined.

The drives also contained enormous amounts of puzzling numerical data that Maria spent several days trying to understand. One evening she announced disgustedly that it appeared to be useless marketing data that had invaded the privacy of millions of people. It had tracked what they viewed on the net, how much time they spent on pages, what advertisements they clicked on, what they bought, how often they returned to certain web pages, and so on.

Gabriel said, "That's probably how the person who owned the data center became rich enough to be able to afford it. The same obsession with information, which led to him prying into billions of people's lives, probably also drove him to amass all the information we're so happy about."

Blossom stroked his head, "I love that you can always see the good in something. My little optimist."

Gabriel, a little embarrassed, said, "Mum, I'm almost ten. Not so little anymore."

There were chuckles around the room at that.

I didn't go on the trek north to Gladstone. The four who went — Ben, Maria, Vikki, and Matt — were gone for a bit more than a week, though they were in constant radio contact, except for a some hours during a couple of storms. The journey north took four long, frustrating days. The coastal roads had deteriorated badly and in a lot of places forest had become quite impenetrable so they had to back-track many times and find another way forward. The drones were a great help to them in scouting out alternative routes around obstacles. When they reached Gladstone they spent two days scavenging, then just two days in the return journey. The way back was much easier because they'd already mapped the easiest route with the help of the drones and the AI. Also, Gabriel had made the suggestion of using the rearward-facing camera of each horse to record time-lapse images of the journey that could be replayed in reverse to make the return journey easier. The AI automatically pruned the sidetracks that branched off to go nowhere, showing only the main path of the journey. Maria, Ben, Matt, and Vikki enthused over that, saying it made retracing their steps much, much easier.

But overall, the journey was rather a disappointment. They didn't come back empty handed, but they weren't really able to find much. All the low-lying areas were flooded. Gladstone was hilly, so some was above the waters, but unfortunately the storms and rampant vegetation had done a lot of damage. The surrounding suburbia had yielded more, but it would take many, many future visits to search it thoroughly.

After looking at some maps, Ben, Maria, Charlie and I decided to check out Roma. It was due-west about four hundred kilometers away, so about three days of travel at an average pace of ten kilometers per hour, if there were no difficulties. On the maps the town looked fairly large, so we figured it might yield some useful things, and being inland was unlikely to be flooded.

We'd previously concentrated most of our explorations on the coast, as that's where the most people had lived and the most shops, warehouses, and industries were, but it didn't take long on the journey to Roma for us to realise travelling out west was much, much easier. Reforesting of the coast had let rains spread inland and what had been semi-arid land had now become thickly covered with tall trees. The previously dry, open, grassy areas we'd seen in photographs of the region were gone, replaced everywhere by tall, dark, rich, moist forest. The roads had been well preserved though, so we made good time. I was very pleasantly relieved that it was such a boring ride. I took the opportunity to listen to some audiobooks. I didn't really need to watch the scenery when my horse was following another because it handled the job automatically, and I could have slept, but I preferred to watch the scenery... despite it mostly being just forest. Perhaps I didn't entirely trust the horse's level of automation. When I tired of the audiobook I'd use the radio to chat with my fellow travellers, and Jill and the others back at the Habitat.

The first two days we were travelling on a nearly level road, through a long, mostly straight tunnel of trees, lit gloomily by a ragged gray channel of clouded sky above. The third day, it rained, not heavily, but persistently. It didn't slow us — we were only going about ten kilometers per hour anyway — but the constant drumming of the rain on the canopy of our horses added, somehow, to the tedium; it made conversation difficult, and there was even less to see outside the horses. I made a mental note that next time I went on a long journey I'd bring noise-cancelling headphones.

By nightfall that third day we'd reached the outskirts of Roma, so we paused for the night so that we could explore the town in daylight. At some point during the night the rain stopped and we woke to a cool and freshly washed day.

We didn't know what to expect when we reached Roma, but we were quite surprised by it. The town had nothing and everything. Puzzlingly, there didn't seem to be anything sufficiently special about the location to warrant the existence of a large country town there, but its isolation and size meant it had almost everything needed to live well there, including a good-sized hospital.

We'd come into Roma on the Warrego Highway, continuing to an enormous shopping plaza and turned right just past it to get to McDowall Street which would take us out to the hospital. We hadn't gone far up Arthur Street when Ben suddenly stopped and broadcast excitedly to the rest of us, "Whoa! Looky looky looky at this!" His horse had turned a little to the right and was standing by a large puddle on the wide concrete area at the side of the building and he was leaning forward inside his horse, pointing animatedly at the ground ahead and to the right of his horse. As we each walked our horses up alongside his to see what had caught his attention, we saw wet bootprints. A person had stepped through the edge of the puddle on their way toward the front of the supermarket, back the way we'd come. We looked at each other in astonishment.

We turned our horses and hurried back around the corner. Ben followed the footprints while the rest of us used the road again. What may have been a dirt or grassy verge, now overgrown with shrubbery and some trees separated us from Ben. His voice came over the radio, "Damn! The tracks faded out." But he kept moving forward. "There are some doors here. They look like service entrances. I'll see if any are open. Dammit! I wish these horses had manipulator arms on the front." One of the drones had detached from his horse and, flapping its wings to stay aloft, it tried each door in turn with its grasping feet. This proceeded without success until nearly at what looked like a glass-fronted cafe. That side door opened. Ben directed the drone to immediately push it shut again in case there was an oxygen-rich environment inside.

We discussed what we should do next.

Ben wanted to go inside the building, "Maybe there's someone in there. We can rescue them... like you and Jill did for us."

Maria said, "They might be perfectly happy here. They might see you as a threat if you go barrelling in there."

Charlie said, "And you don't know how many there are. What if you go blundering into another slaver nest."

Ben's eyes widened. He clearly hadn't considered that possibility.

I thought for a moment. "We should send a drone in. They have lights. It could scout out the interior to see if it's safe. Worst case, we lose a drone."

Everybody nodded and Ben sent two drones back to the unlocked door. One opened it and the other landed and waddled inside on the ground while the first closed the door then stopped flapping and just hung from the door handle by its feet, waiting there 'til needed. Ben sent the video feed to all of us from the drone inside the building, and we all watched as he made it pan the view around itself. It was in some kind of maintenance room. Nobody there. Across the other side was another door. Ben launched the drone into the air to open the other door and slip through... into the interior of the shopping plaza. The drone gained height and found a place up high to perch where it could see as much as possible.

Maria said, "Remind me later to add speakers to the drones. It would be really useful right now if we find anybody in there. We'd be able to explain to them."

From back at the Habitat, Vincent's voice came through the horses' radio, "Good idea."

"Thanks Dad."

Vincent added, "Ben's suggestion of arms on the horses is too. I don't know why nobody thought of that before."

Maria asked, "How long have you been online?"

"Since breakfast, we've been in the main livingroom with your sound feed coming through the big screen. We've been working on other stuff with your sound in the background. Since the video came on we've been sitting, watching. That's Jill and Gabe, and me."

I said to Jill, "Hi honey."

She replied, "Be careful, sweetie."

"Yep. Always."

Ben sent the drone flying through the large shopping plaza. We saw some disturbed stacks of goods and a lot of food had gone from some of the shelves. Someone had definitely been scavenging here. But either they were hiding or they had gone. After making another couple of sweeps of the interior, Ben brought the drone back through the entry door, which had been reopened by the other drone, then flew it up high, circling to see if it could spot anybody moving around in the streets... but no-one could be seen.

I said, "Looks like that ends our intention to scavenge in this town. If someone else is living here we can't take their supplies."

Charlie said, "We should use the horses' external speakers to to announce that we're friendly and that we want to help... that we have food and other supplies for anyone who wants it."

We all agreed.

Charlie added that the message should come from a female voice as they're less threatening.

I thought Jill had the most appealing voice and that the message would be best coming from her. She thought I was biased, but the others all agreed with me, so we hammered out what might be the best wording, then Jill recorded it and sent it to us as an audio file. I put the announcement on a timed loop to repeat every thirty seconds, speaking from my horse.

Maria pointed out, "Our external microphones should already be on by default, but we should check them now to make sure, just in case someone calls to us from outside."

We spent a while walking around several of the nearby streets with my horse blaring out the message and a few drones flying high, but we didn't see anyone, so we continued our original course to the hospital.

We were quite relaxed before, when we didn't know people were living here, but now we were very tense. I wasn't sure about the others, but I kept thinking of what Charlie had said about the possibility of slavers being here and it really set me on edge. And, unlike the others, I hadn't experienced the slavers' abuses! I expected that the others were feeling much more stress than I was, though I later found out I was wrong in this. The others were, of course, very alert, but they weren't freaked out to the degree I was.

I asked, "Ummm... what's the point of still going to the hospital? We can't scavenge anything there, now that we know there's people here."

Ben was in the lead and Maria behind us. Charlie's horse was walking beside mine. I saw him look across at me, in the shaded dimness of his canopy, his face lit by gray road and occasional parked, dusty car. His voice came over the horse internal comms, pausing when Jill's message looped through my external loudspeaker, "We might yet meet the people and bring them back with us, in which case any medical supplies we find could be very useful. If everything in the hospital has remained untouched in all this time it's unlikely it ever will be used, so would be better off with us. On the other hand, if the medical supplies have been used then they might be running out of some things, so if we manage to contact them and they don't want to come back with us, we might be able to help restock theirs for them and create goodwill... allies."

I nodded.

The hospital was almost at the West edge of town, but that was only several blocks away — Roma was not enormous — so it didn't take long to get there.

It was hard to imagine what it would have looked like without all the trees, but back when it was much drier and more open I imagine it probably would have been a nice, spacious, airy, country town. Now, with the increased rainfall, it was being invaded by forest.

When we reached the hospital we released a couple of drones to do a preliminary reconnaissance inside the main building, like we had at the supermarket. When we were satisfied that all looked pretty safe in there, Charlie and Maria squatted their horses down, camel-like, in the open parking lot away from the tree cover. They slid the panels forward that covered the opening that was the attachment point for their suits, which they everted. Then they wriggled into the suits and carefully sealed and detached to go explore the interior of the hospital.

Ben and I stayed on lookout in our horses in the parking area. I remained acutely conscious that there were other people in Roma somewhere, and that they might not be friendly. My horse was still repeating the announcement to anybody that might hear. We kept another couple of drones aloft, watching for any movement around us, but apart from the paved parking areas and the roads, everything out here was obscured by trees. The hospital had originally been surrounded by open fields, which were now tall forest. The shadows under the canopy dark beneath the thick, gloomy, cloud-covered sky.

I muttered, "Might be in for more rain."

We could hear Maria and Charlie talking about cupboards and boxes and packages as a background. They could hear each other at full volume while our voices were dampened, while Ben and I heard each other at full volume, but the voices of Ben and Maria were reduced a little so that we could all carry on multiple conversations without interfering. At any time we could override that to make important statements to everyone.

Dahlia came on the radio at the Habitat. They could choose who they wanted to speak loudest to. "Hi folks. Little Hope and me are part of your audience now too. Kim, can I ask you to move your horse over close to some of the trees in front of you over at the edge of the parking lot, so I can get a better look at the leaves of some of them?" I did so, aiming the horse's camera at one tree's leaves, then moving to another, and another. She said, "I thought so. These are coastal rainforest trees. How on Earth did they end up way out in Roma? Especially since there are no animals to pollinate flowers anymore..."

Jill suggested, "Maybe flowers are being pollinated by wind."

Dahlia's voice was doubtful, "Maybe... but the fruit of some of these is quite heavy. It's unlikely they could travel 400 or more kilometers... even over 50 years."

I said, "There's always a lot of debri after storms. Perhaps bits and pieces of vegetation — leaves, small branches, even small fruit — are blown long distances and some just take root where they fall. As the climate inland became wetter, stuff blown in from the coast would be increasingly likely to put down roots and survive. There's probably some selection going on too. Plants that have bits more likely to break off in a storm are naturally more likely to spread. Plants that grow from pieces would be favored too."

Charlie's voice came louder from the horse comms, "Well, good news. Everything is untouched. Seems like any people still living in Roma have no interest in the medical supplies here. Maria and I are filling our bags with as much as we can carry. We'll be back out soon. I think we'll get a second load too. We can come back in the future for more. We're just bringing the most important stuff for now."

Not long after that, Maria and Charlie came out, each carrying two large fabric bags filled with scavenged goods. They flipped up the covers on the rear storage sections of their horses and pushed the bags in. Then they went back to the building for more.

Soon they returned, each with another two bags, which they also loaded into their horse storage compartments and locked them closed. Next they each went to the side of their own horse, near its nose, slid the entry port cover aside, carefully re-attached the front of their suit to the entry port, zipped it open, wriggled out of their suit and into the driving cockpit, then pulled their suits inside-out after them, and slid the rigid cover panels closed.

Ben said, "Okay, lets see if we can find some people, then head home."

We turned our horses and started back the way we came, the message still repeating from my horse's loudspeaker. It was only mid-morning — about 9am — but we wouldn't be doing any more scavenging. We'd left two horses (Ben's and mine) empty in case we encountered people who wanted to return with us. Each horse's luggage compartment could carry two people, or three in a pinch.

Unhurriedly meandering around the town, to cover as much area as possible, we were going south, along Hawthorne Street, just a block west of where Ben had spotted the footprints and a heavily covered person came running out onto the street from a low, modern-looking building on the left. They were waving their arms and shouting, "Hello! Hello!" — a woman's voice somewhat muffled by the oxygen mask she was wearing.

I switched off Jill's message and spoke instead, "Hi, I'm Kim. Do you need help? How many people are here?"

Her voice sounded panicked, "I'm Sally. I'm the only one. Can you take me with you? I heard you earlier and couldn't get to you in time. I thought you'd gone and weren't coming back."

I looked questioningly at the others and asked on the internal comms, "What do you say, folks?"

Jill answered from the Habitat, "How could we not?" I saw the others nod.

I switched back to the loudspeaker, "Okay Sally, hang on a moment while I set this down and get out." Then I settled the horse down on its belly, slid the port cover aside, pushed the suit back out, squirmed backward into it, sealed up, and detached from the horse. I noticed Ben had squatted his horse and was getting out too.

I walked toward Sally, "The journey back is about 3 days. You'll need food. Do you have any with you?"

She nodded and led me, followed by Ben, back into the building she'd come from. As we approached I could see through the glass doors, even with the grime of decades coating them, that it had been a library. She heaved the sliding door aside enough for us to enter, then slid it closed again. Now inside, she turned off the canister at her hip, then pulled off her hat and mask, revealing a lined and tired face which was suddenly illuminated by a beautiful smile, despite her broken and missing teeth. "The air's okay in here. You don't need your gear."

I shook my head, "We can't take them off. I'll explain later."

Our bodycams were on and I heard Vincent comment in my earphones from back at the Habitat, "A library. They had to maintain a constant climate to protect the books. It would be a good place to seal up. And in the middle of town, with great access to everything. Good choice."

Sally went over to one corner where there were a lot of cushions and blankets and open and closed food boxes. I guessed that was where she slept. She emptied a lot of the boxes into a bag — its strap over her shoulder, then picked up another, much heavier bag, already full of things, presumably from a recent scavenge trip, and slung its strap over her other shoulder.

Maria, still outside in her horse, presumably watching through our bodycams said, "Ask her how she gets breathable air."

I relayed the question to Sally and she pointed to a machine in another corner. It had obviously been constructed after the calamity.

"Did you build this?" I asked.

"Nup. Frank did. He died ages ago." I was about to ask Sally how it worked, but she strolled over to it and pre-empted my question by saying, "It's pretty simple. It just takes air from outside." She pointed to a pipe. "Water vapor is filtered out. The air goes into this chamber where it's cooled to minus 79 degrees Celsius, when the carbon dioxide freezes as dry ice. The remaining air is vented inside, and the dry ice is thrown away... well, not thrown away. It is allowed to build up around the cold chamber to help cool the next load of air, but is sealed off from the living area so that it slowly vaporises back to the external atmosphere." She shrugged. "Easy."

Maria asked, "How does she cool the air?"

I asked Sally.

She pointed to a non-descript, fat, tubular, metal device, "It's like a refrigerator compressor, just a simple heat pump, but it's filled with helium instead of freon or ammonia. Two pistons alternately compress and expand the helium in different parts of it. It's powered by solar panels on the roof." She pointed up.

(Looking back on that, writing this now, I'm surprised none of us had noticed the lack of tall trees around the library. Sally had lopped them to avoid shading the solar panels. Remembering that now, it looked really obvious, but none of us had seen it. A demonstration of mindset, I guess. Like the video where the viewer is asked to observe a basketball match and count the number of times the ball is passed, then afterward they're asked if they saw the gorilla. You can see that video at https://www.youtube.com/watch?v=IGQmdoK_ZfY.)

I said, "Okay, anything more you want to bring? We have plenty of air and water for the journey back."

She looked around, then shook her head, "Nup. Great place to live, but I don't wanna die alone here. Time to move on." She donned her hat and mask and turned her air canister on again.

The three of us headed to the entry and she heaved it aside for us to squeeze out. She followed, then pushed the door closed. She lingered for a few seconds looking through the filmy doors into her home of countless years, then turned away to us, her rescuers.

Ben went to his horse while I led Sally to the back of mine and opened the luggage hood. Same as in all the horses, inside the empty space, attached to the wall that divided it from the cockpit, was a spare seat for emergencies. It folded down from the wall, putting her and me back-to-back, but separated by the airtight partition. The hood, like most of the top surface of the horse, was covered in solar panels. Like the ones on the front canopy, they could hinge up outside the transparent cover like louvres, still shielding the interior from some of the heat from the sky, but allowing a passenger to see out, making it less claustrophobic and less motion-sickness inducing. The compartment didn't have a video screen or any luxuries; it was purely for luggage or emergency. I explained that once I was back in the horse myself, I would turn on the valve to fill the compartment with good air, but that she should not turn off her own air canister until I let her know. I pointed out the water bottle and the simple toilet like the one in the front compartment. I briefly described its use to her. Once she and her luggage were inside, I showed her how the seat belt worked and how to operate the hood release if she needed to exit in case of an accident. Then I pulled the hood down and clicked it closed.

The luggage space of Ben's horse was still empty, and after a little discussion as to whether we should head back to the hospital or look for other things to scavenge, we went for more medical gear. And then we were on our way back home.

The three days back to the Habitat were much more interesting than the journey out. Sally told us about her past, and we filled her in about the Habitat.

It turned out that she was much younger than her appearance. I'd initially guessed she was in her seventies, but she was probably only in her forties. She had been born after the catastrophe and had grown up in this world.

Condensing down all she said during those three days of travel, she was raised by her mother, who died some decades ago, and Frank, who died more recently. There was another man who had perhaps been her mother's husband, but Sally didn't seem to know much about him and only briefly mentioned him.

It was difficult for Sally to put dates on things because she hadn't ever bothered counting years, and with nobody to talk to about all this, it all just blurred together. Her very early childhood had been on a farm some distance outside Roma's township, but she was so young she didn't remember anything of it. If her mother hadn't talked of it as she was growing up, she would have thought all her life had been in the town. Initially she and her mother had moved into Frank's place, an engineering workshop on the south-west part of Roma. Later, in Frank's electric car, they moved to the Library because of its central position, close to food and other things. Sally had only a vague memory of the move to the library. She was a young child at the time. Her mother had died before Sally had her first period, so she had no idea what was happening to her when she'd started to bleed. She'd been terrified. She'd thought she was dying.

Home, for most of her life, had been the library, though she had been back to Frank's old workshop many times, and had explored most of that engineering part of town with him. They'd also gone on scavenging trips up to the airport in the north edge of Roma. Frank had dreamed of putting together an electric plane so that he could explore greater distances, but although he spent a lot of time working on it, he never completed it. He died many years ago, the project far from finished.

Sally's favorite thing in the world was to read books. She'd read every book in the library and most of the engineering manuals that she and Frank had salvaged from the workshops. She'd been ecstatic when she'd found the libraries of the TAFE, college, and the schools. Later, she'd begun exploring houses for more books. Some had very large collections and she'd always got a huge rush of pleasure when she discovered them.

When we told her of our collection of hundreds of thousands of ebooks, audiobooks, Wikipedia archive, and movies, she could hardly contain her excitement. She'd never seen a movie, though of course she'd often read about them. And she loved the idea of audiobooks.

On the third day we were each talking more about our childhood. Jill and I talked about our upbringing in the early days of the Habitat, being around all the scientists and engineers.

Maria, Ben, and Charlie talked a little about growing up under the slavers.

We all spent a lot of our time talking about our interests and what we liked.

We arrived home after nightfall on the third day. We normally don't travel at night, but that final day of the trek we were so close and we were all impatient to get home, so we pressed on. Maria volunteered to take Sally through decontamination, and sterilise the packages of medical supplies.

We all met up in the big living room where Sally was introduced to everyone. Of course, we'd all been talking over the horse comms for three days, but meeting in person is always different.

It had become obvious during the journey back that Sally was best suited to helping in the engineering labs. Vincent and Maria took her under their wing.

Sally wanted her living quarters to be in a room under Savanna-1; it reminded her of Roma when she was little, before the forests invaded. That was understandable, especially considering she'd spent so much of her life alone. And Savanna-1 was in the environment next to Temperate-1 so she wasn't far away in the event of an emergency, and we were all linked by comms anyway. It wasn't unusual to feel the need for privacy. Jill and I often wished our bedroom was further from everyone else's. Kayla spent increasing amounts of time in one of the apartments near the engineering labs. Cliff often wouldn't be seen for days, being consumed by his experiments in the genetics lab, and sleeping on a couch there. Dahlia and Matt had moved to an apartment separate from, but linked with the main living quarters, though that wasn't so much for privacy, but because they were worried baby Hope's crying at odd times of the day and night would disturb others, which was thoughtful of them. So nobody raised their eyebrows at Sally's desire to be apart.

Everything seemed to be fine for a few months, except we noticed Sally was missing for longer and longer periods, and when she did show up she often looked worn and sick. On those occasions she would show an unexpectedly quick temper. After a day or two these shadows would pass and she'd seem to be her usual sunny self again, though with gradually decreasing patience. It became particularly noticeable to Vincent and Maria when she'd encounter technical problems while working on something with them.

One evening, at the evening meal/meeting Sally stunned everybody by angrily accusing Vincent of trying to rape her. Vincent protested his innocence and she fled the meeting to go back to her apartment in Savanna-1. Vikki followed her to try and talk with her. At the meeting, many of the people were finding it difficult to look at Vincent. One by one most of those present made excuses to leave early. Just Maria, Blossom, Charlie, Jill, and I remained with Vincent when Vikki returned.

"She wouldn't let me in, but she came out of her apartment and we talked." Vikki glanced at Vincent. "She was very convincing."

Vincent frowned, "I didn't try to rape her. I haven't even touched her. I mean that literally — I haven't touched even a fingertip to any part of her. I definitely haven't threatened her in any way."

A light of realisation went on in Vincent's face. "Ahhh. I know what it is. I know what's happening. I know why she wouldn't let you into her room, and I know why she so often looks sick and her temper is frayed. And I know why she's making up horrible stories about me. I'm the only one who knows she's an alcoholic, right?" He looked around at us and it was clear this was news to all of us, though Charlie looked less surprised.

"I found out by accident a several weeks ago. She begged me not to tell anyone, so I didn't. Initially we would talk about it quite a bit — I think it was a relief to her to be able to discuss it with someone. She said she was trying to reduce her drinking, and that it had temporarily got a bit out of control recently. She insisted that she wasn't addicted because she could go for days without drinking. I'd talk about how addiction, tolerance, and withdrawal are really different aspects of a single thing, and why I think letting youself be held ransom by a chemical was risky. After a while she started to get angry at me and accuse me of moralising. I couldn't work out why she would say that. I kept telling her I don't see how morality has anything to do with it. Addiction is just a mistake, an error, simply a result of how homeostasis works. The example I used is that morality has nothing to do with getting something in your eye if you use the grinder without face protection. It's just mechanics. But she never seemed to hear me. I think I understand now. I think she has a lot of guilt about her drinking. And she's become scared I was going to expose her alcoholism, so she's decided to discredit me first by fabricating this assault, making me a villain so that nobody will believe me."

We were all quiet.

Vincent pursed his lips, "There's something else. For the past few weeks she's become increasingly angry at me, misinterpreting what I say, to make them into slurs or insults. Has this been happening to anyone else?"

Maria nodded, "Yes, I've noticed that too. I've seen her do it to you a few times, but she's also done it to me on a couple of occasions. One time I complimented her lathe work and she snapped at me to stop putting her down. I was surprised and thought at the time that it must have been my mistake, that I must have sounded insincere, somehow. Another time she got angry and stormed out, saying I was accusing her of theft, when I simply asked if she'd seen where the bottle of solvent... Oh! Ethanol! Ethyl alcohol! She probably did take it and was being defensive. I never did find it. I had to go to the storage room to get another."

Charlie had been silent until now, "If alcoholism is her problem then that brings a lot of difficulties along with it."

Vikki frowned at her husband, "You're assuming she's at fault here?"

Charlie shook his head, "I'm not assuming anything. I said 'if'. I think we should consider all aspects."

Vikki growled, "When she's not here to defend herself. You haven't heard her explanation."

Charlie gave Vikki a pleading look, "And I'm perfectly willing to hear it, honey. But we also can't ignore the rest of the possibilities." Vikki crossed her arms and settled back in her chair, frowning. Charlie continued, "If she's alcoholic then there are a few associated problems. Firstly, and most importantly, she can't suddenly stop drinking, because alcohol is unusual among drugs in that suddenly withdrawing from strong addiction can kill the alcoholic. The only way out is to gradually wean herself off, or else use anticonvulsant drugs to weather the storm. Neither is a good option, and I don't think we have any anticonvulsants. Secondly, some people are affected really badly by alcohol and develop an alcoholic psychosis, with paranoia and delusions, and these problems don't go away by ignoring them or pandering to them — they get worse... though I think B vitamins can help in some cases. I'm not saying this is what Sally has, but if it is, then I..." he looked at his wife, "we need to learn more. I have to admit, I've recently read about alcohol because I smelled it on her, but I didn't say anything earlier because if it doesn't cause problems then I figure it's her business."

Vincent looked glum. He spoke softly, "There's no way for me to prove my innocence; it's just my word against hers. Unless she admits she made it up, I know this will hang over me forever. Some of you will always wonder if I really did it, and I can understand that. There's nothing I can do or say that will ever erase her accusation. From now on I'll be wearing a bodycam. I wish I'd been wearing one earlier."

I said, "I think that's a good idea. I think we should all do so. Trust is our greatest asset. We need to be able to trust each other. When interacting with Sally, we should be in pairs, or if alone we should be wearing bodycams."

Annoyed, Vikki said, "You're acting like you've already decided she's to blame."

I shook my head and tried to maintain a soft, reasonable tone, "No, I'm acting like I don't know and don't want to jump to conclusions one way or the other. Remember, bodycams also protect Sally."

Vincent said, "Look, I get that she's probably had a traumatic upbringing--"

Blossom spoke up angrily, "Oh bullshit on that! We all had things that were good and things that were rotten. She wasn't raised by slavers who raped, beat, and threatened to kill and eat you. She doesn't get a free pass for long-ago stuff. Fuck that! We know Vincent. I've known him all my life! Has he ever threatened anybody or sexually pressured anybody? I don't care what her story is, as far as I can see, she's the one doing the sexual threatening, the bullying, not him."

I stood. "I'll try to talk with her. I was her first contact and we spent three days in my horse on the way back from Roma, talking. Maybe I can help resolve this."

Jill stood too. "I'll come with you."

"Might be less intimidating if I go alone. I'll get one of the bodycams first."

Jill and I left. I don't know how long the others kept talking, or if they continued at all.

I called Sally from our room on the Habitat's intercom. She put off meeting with me until the next day, so Jill and I went to bed early. But we stayed up for hours talking about the problem of unprovable accusations. We'd read a lot and watched a lot of videos about such controversies from the time before the disaster, so we understood how men back then, especially men of high social standing, got away with assaulting women. Such assault was almost always in private, meaning women often had a very hard time proving it. There was a long history of this, eventually making it very difficult to believe any men who protested their innocence. On the other hand, we also knew of cases, from that time, of men who really had been frivolously accused of assault.

In both instances the victim suffered from a situation where proof was impossible and they were not believed — the woman in the first example, and the man in the second.

There were other examples of unprovable accusations too. Racists caused problems that were often difficult to prove. Lesbians and gay guys and transexuals used to be illegally discriminated against in many ways, but proving it was often difficult or impossible. Likewise for disabled people. All these caused innumerable people heartache. And now, here we were, facing our own dilemma.

I've long felt one of our strengths, Jill and me, as a couple, is that we generally didn't adopt opposing views and try to convince each other. We both switched viewpoint constantly. It was like a single person weighing up arguments for and against something in their mind, except we were two minds doing it, each trying to discover all the arguments on both sides of a particular topic.

I said, "Vincent has never done anything like that to any of the others."

Jill said, "That we know of."

I gave her a skeptical look. "Oh, come on. He's pretty old."

"Don't men retain their sex drive into old age?"

I shrugged. "Do they?"

Jill said, "He's not the strongest person, though, and a normal walking pace would be enough to escape him."

I said, "That's not really the point though, is it? Nobody should have to."

Jill nodded. "True. If she's been traumatised by her past, then she shouldn't have to put up with some creepy old guy leching."

"I really can't imagine Vincent doing something like that though."

"Nobody can truly know what another person will do."

I wasn't so sure. "People operate within certain parameters."

"Can we ever truly know what those parameters are?"

I said, "What about erring on the side of the weakest?"

Jill raised her eyebrows, "Yeah, because that never goes wrong. The schoolkid who owned up years later to having falsely accused a teacher, long after it had destroyed his life, career, and marriage?"

"Oh, yeah." I nodded my head.

"Alternatively, you can't distribute blame to both because that obviously adds further injury to the one who was wronged--"

"--and discourages people from stepping forward."

She nodded, "Right. And you can't ignore the situation simply because it seems undecideable, because that encourages the wrong-doer to continue."

We kept discussing it for a while, unable to come to any real conclusion, before eventually deciding to sleep on it.

The next morning, wearing the bodycam, I went to meet Sally on what we still called the "surface" of the Savanna-1 environment, even though it was now buried by Kayla's antbots. The goats spent most of their time in their other, larger, more recently excavated, newSavanna environment, but still tended to return here at night. Capri was now adult and had twin kids of her own that she was nursing. I'd brought the little trolley with me and was milking Capri when Sally walked over to the goat castle where I was seated.

"Hi," I greeted her, trying to sound friendly and open.

She waved back, but avoided looking at me, then sat on one of the steps on the outside of the castle. She seemed worn, with dark rings under her eyes.

"Are you all right?" I asked.

She visibly bristled, "Why?"

"You look tired." I scooped a cup of milk from the bucket and held it out toward her.

She shook her head and dismissed the offering with a wave of her hand, so I slowly sipped it instead.

I couldn't think of how to open the conversation with Sally. It was very awkward, worsened by the fact that she seemed easily angered already. So I sat, gradually taking the milk in tiny mouthfuls, delaying, while trying to think of a way to broach the subject, and coming up blank. Since waking this morning I'd been trying to think of a way to talk about this, and failing. I was actually dreading this and was wishing I'd never volunteered to do it.

"What did you want to talk to me about."

Okay, no time to come up with an easy intro. "We need to talk about Vincent, and your accusation."

A dark look at me with narrowed eyes. "Are you calling me a liar?"

"No! Why would you even go straight there?" I was feeling a bit panicked.

She was cold, implacable. "It's not complicated. What more is there to say?"

"Lots. You dropped a bombshell then left the room." I felt a note of pleading creep into my voice. It irritated me.

"Okay, he's scum! He's a sexually abusing psychopath!"

I shook my head despairing that this was not going well. "No, what I mean is, can you explain what happened?"

"Why? Why do you want to know?" She seemed suspicious.

"Well, so we can understand. Jill and I have known him for a few years and the others have known him for most of their lives — some of them, for their entire lives. It doesn't fit well with--"

She exploded. "So you don't believe me!" She yelled at the top of her voice, "Screw you!" making Capri and her two little ones skitter away. Sally turned on her heel and stormed off.

I sighed, and muttered under my breath, "Ugh, that went terribly." Well, now I knew what I was going to be endlessly revising in my mind for the rest of the day. That was definitely the wrong thing to say... I should have found a better way.

It didn't take long to trudge back to the living quarters, and I was still glumly mentally kicking myself. I'd just put the milk bottle away in the fridge and Jill came up behind me to give me what I thought was a consoling hug and a kiss on the side of my neck. I said, annoyed at myself, "I blew it, really badly."

She turned me to face her and shook her head, smiling at me, "No sweetie. You solved it." She smiled at my puzzled look, "As soon as Sally returned to her rooms she called me on the intercom. She said you tried to kiss her and push yourself on her."

My jaw dropped open. "Wha...?"

Jill said, "Big mistake. She couldn't know that I wouldn't have believed her even if you weren't wearing the bodycam. I think we can safely say she made up the accusation about Vincent. I mean, it isn't proof, but it is pretty convincing."

I hugged Jill again, relieved, feeling myself relaxing. "I think I need to sit down."

We sat on the lounge, her arm around me, my head on her shoulder. She spoke softly, "We're not out of the woods yet, though. Someone still needs to talk to her about all this. And we all need to work out what we do about someone who deliberately poisons relationships and sabotages trust. She's obviously sick somehow and if Vincent is right about her being an alcoholic, then she's probably making herself worse." She sighed. "I have absolutely no idea of how to manage something like this."

"I guess we hit the library and see what we can learn about it."

She nodded. "Charlie's already been learning what he can, so it makes sense to coordinate with him. And I'll let Vincent know what happened. I'm sure he'll be very relieved to hear Sally effectively cleared him."

But we didn't get up off the couch. We were content to stay like that for another long while. Even though it was still early morning, I could have happily fallen asleep there, such was the relief from the tension I'd been holding.

At the dinner meeting that night everybody except Sally was present. That wasn't unusual, but I was silently thankful that she'd decided to stay away tonight.

Jill started the ball rolling, "We need to discuss Sally and what we can do to deal with her."

Dahlia said, "Shouldn't we have her here during the discussion? It doesn't seem right to be talking about her behind her back."

Jill said, "Well... it's actually a good thing she chose not to be here tonight. The discussion would be a good deal more awkward if she was present. And I don't see it as talking behind her back — rather, that we are preparing ourselves for a storm... because that's what she is. You all know she made some accusations against Vincent. Kim and I have only known him a few years, but you folks have known him for most or all of your lives. Has he ever seemed to any of you the kind of person who would force himself on someone?" She paused for a moment... nobody spoke. "Well, this morning Kim went to talk with her, but Sally lost her temper with her then called me and said that Kim had made sexual advances on her and tried to kiss her." She raised her hand holding the remote control for the entertainment screen. "But Sally didn't realise Kim was wearing a bodycam. Let's have a look, shall we?"

We all watched the short video from my point-of-view, including my walk back to the living quarters where I put the milk in the fridge and Jill told me about what Sally had said. When Jill switched it off she raised her eyebrows and looked around at everybody.

Vikki said, "That is pretty damning. The way her temper flared up so suddenly is scary too."

Charlie said, "We — Jill, Kim, and I — have spent the day finding everything we can in the library on alcoholism. It's a much more complicated problem than I expected."

Vikki asked, "Is there any actual evidence that she drinks to excess — that she really is an alcoholic?"

Vincent said quietly, resigned, "Well, before her whole anger thing, she and I used to talk about her alcohol intake. It certainly is excessive... she was worried about it too, but later, when she started getting defensive and angry, she began believing that she wasn't addicted and that she could stop anytime she wanted. She'd get really jumpy and her hands would tremble is if nervous. Then she'd drink really heavily again — 'self medicating', she called it."

Charlie tapped the table with his index finger. "The puzzle we have to solve is what to do. She's both very vulnerable and potentially dangerous. From what I've learned, it seems like the alcohol is damaging her, perhaps through a combination of long-term drinking and her uninformed attempts to stop. At the same time her willingness to destroy friendship and trust makes her a dangerous bully."

I grimly drew the obvious conclusion, "And ages ago we decided that we couldn't allow bullying here. It's too risky. Our lives depend completely upon trust to protect us from the world outside."

Ben protested, "We can't just throw her out. That'd be murder. We'd be no better than the slavers. We'd be the bullies."

Jill waved her hand, "It's okay, Ben. We're not talking about throwing her out. We're just trying to get perspective on the importance of the problem we face. We need to work out some way to help Sally get well, or... ummm..." She paused and shook her head. "I can't see a second option. Can anybody help me here?"

I said, "Everything I've read on the topic says you can't make an alcoholic get better; they have to choose it themself." I turned to Vincent, "You've known about her problem and been looking into it longer than anybody else..."

Vincent looked a little embarrassed, "I didn't really research it. I don't know why. I guess if she had a machine that was broken I would have, but it didn't occur to me to find out more about a human problem."

Charlie said, "I've been reading as much as I can find about it, but from what I've been able to learn, Kim is right. It would seem that only the addict can decide to stop their addiction and nobody else can convince them of that. It seems really cruel, but if other people help them, it just prolongs the problem, worsens the damage, and provides them with excuses and other people to blame for their own failures. They have to be allowed to hit rock bottom and decide on their own. So... what can we do until then? I have no idea."

He looked around at us all, "If the alcoholic does decide to get better then that changes everything. Having supportive people who can help becomes extremely important. An organisation called Alcoholics Anonymous existed in the old days, and people who were trying to get better were helped by other people, usually ex-drinkers who called themselves sponsors. I don't know much about that yet. And I don't know if any of us could do it, as we haven't experienced alcoholism. I need to learn more about it. I'm currently reading what Alcoholics Anonymous called their Big Book. I still don't know if it's going to be a help to us."

(Alcoholics Anonymous' Big Book is at: https://www.aa.org/pages/en_US/alcoholics-anonymous.)

Dahlia said, "Maybe we can give a copy to Sally. Perhaps it can help her directly."

We all thought that was a very good idea.

Kayla said, "I don't think there's any way to send it to her tablet computer. We can draw her attention to it, but she has to decide to download it."

Gabriel smiled grimly, "Almost a metaphor for the main problem."

We all looked around at each other. Obviously everybody was wondering the same thing. A few people looked at me. "Nope," I said, "I'm not taking it to her. Her temper scares me."

Ben said, "I'll do it."

Blossum said, "Be careful. You're strong, but that won't matter if she gets angry and has a weapon... knife, or something."

"I'll be fine. I've survived worse."

Judging by the all scars on his face, neck, and arms, that may have been true.

Ben didn't want to waste time waiting until morning, so Kayla put the book on a flash drive that could be plugged into Sally's tablet, and I clipped a webcam to his t-shirt. Equipped with a radio earplug and a torch, he walked through the night to Savanna-1. Next to the airlock inside Savanna-1 was the small building set against the Habitat interior wall. He opened the glass door, walked to the far side of the room, and down the stairs to all the labs and storage rooms, and living quarters. He went to Sally's apartment, knocked on her door, and waited... knocked some more, and waited...

I tried calling her intercom, but she didn't answer.

Ben said, "She might have had an accident. I'm going in."

We all watched his bodycam's view on the big main screen as he opened the door, called out to her, and switched on the light. He searched all the rooms, but she wasn't there. Her bedroom had a large collection of empty bottles in one corner.

Kayla spoke quietly, "I know where she is." She turned her tablet to show us the horse tracking program. "She's taken one of the horses and is about sixty kilometers west. Probably returning to Roma."

Maria said, "She must have started about midday."

Ben said, "I'm coming back."

I called her horse's radio. She didn't answer, but I assumed she was listening. "Sally, if you'd asked we would have given you the horse. You can relax on that count: the horse is yours. We won't come to get it back. It's a gift. Always remember that you're welcome to return here any time. If you need anything we will try to send it to you. If you ever need any help, just call us on the radio. Stay safe and well. Please understand we bear you no ill. We hope you get better." I stopped transmitting, looked at Jill who nodded, then around at everybody else.

Blossum growled, "Bear her no ill! I sure do. She was deliberately trying to hurt people — to bully them. I had enough of bullies under the slavers."

I understood how she felt. Hell! Sally had tried to poison Jill's love for me. I frowned and shook my head. "But she's sick. Can she be held fully responsible for her actions?"

Blossum gave me a critical look, "Okay, I believe you that you can 'theoretically' forgive her." She made airquotes with her fingers. "But tell me truthfully... if she returns here one day, will you ever really trust her?"

I thought about it for a bit. "I think so... after some time... I think I'd probably remain wary of her for quite a while, but yes. If she gave up the alcohol and genuinely tried, I'd give her more chances. Even if she failed multiple times, with occasional temper flare-ups, if she was contrite--" Blossum raised her eyebrows "-- uh — if she was sorry, then I'd give her more chances. She's ill. The alcohol has damaged her emotions and her thinking. How can we blame her for that?"

Jill put her arm around me and kissed my cheek.

One part of my radio message to Sally had bothered Kayla, and she came to dinner a couple of weeks later with two new drones, both entirely black. All conversation died away as she entered the room, with everybody looking with great interest at her new creations. One drone had long wings folded the way a bird's wings fold, but still extending back and up, about a meter beyond the body. The other was much smaller, with short, stubby, relatively inflexible wings. Both had bodies about the same size: about a meter long, and no wider than a person's head. The one with the small wings had a second, shorter tube mounted on top of the rear half of the main body.

She put them both carefully on the floor, then turned back to us and, glancing at us from time to time, explained in her soft voice, "Kim, when you told Sally that we'd send her help if she needed it, I realised we had no good way of doing that. Any help in a horse would take three or four days to get to her. In an emergency that would probably be much too late. That's also a problem for our own scavenging expeditions, and we're exploring further and further away. If help was needed it could take many days, depending on how far away our team was. I kept thinking about it, and eventually had the idea of a rescue drone."

She squatted by the one with the big, folded wings, "These two drones work different ways. This large one is the slower of the two, though still much faster than a horse. It flies like an albatross, mostly gliding, only occasionally needing to flap its wings. The entire top surface is covered with quantum dot material that will efficiently convert light to electricity letting it fly indefinitely, so its range is... well, potentially unlimited. But it can't do well in heavy storms — the low light levels and strong winds — and at night it would have to land. It would use up its charge in just hours flying without light replenishing it. Getting airborne again is a bit of a problem at the moment. I'm still trying to perfect that... doing experiments in the large Savanna environment..." She paused in thought, for a little while frowning as if she was turning something over in her mind, then gave a tiny shake of her head and continued.

"The smaller drone has a jet engine," she pointed to the cylinder mounted on top of the short-winged drone, "but since there's not enough oxygen in the atmosphere to sustain combustion, it has to carry its own. I think it should manage about six hundred kilometers per hour... maybe more... maybe less. And I'm not sure how long it will fly for... I'm guessing maybe an hour. Maybe a lot less. I'm not sure how to calculate fuel consumption, so I might need greater fuel storage. I haven't been able to give it a proper test yet. The whole thing is hollow and contains fuel, except for a small compartment in the middle. The drone is empty of fuel at the moment."

I said, "If it carries its own oxygen, doesn't that make it a rocket?"

Gabriel shook his head, "Rockets get all their thrust by shooting fluid (usually superheated gas) out the back. Jet engines get most of their thrust from the air they suck in the front and blow out the back. The burned fuel blasting out the back helps too, but not so much. The controlled explosion of fuel out the back mostly turns the turbine, which is directly connected to, and turns, a larger set of propellers at the front. They give most of the thrust... like the propellers on the quadcopter drones... except in a jet they turn way faster, which is why they can fly at such high speed."

Ben whistled. "Six hundred kilometers per hour! At that speed it could reach a scavenging team in Brisbane in just ten minutes? Is my arithmetic right there?"

Kayla nodded.

Charlie said, "Or to Roma in just half an hour."

"I haven't tested it properly yet. It could explode, or barely fly at all. I'm not going to test it inside the habitat. I'll go outside to do that. The larger drone — the albatross — I've already tested in the newRainforest environment... though I haven't yet worked out how to relaunch if it has to land overnight, or to protect itself from a storm."

The next day, some of us accompanied Kayla outside to test the new jet drone. We, including Kayla, stood about fifty meters away from it in case it exploded. The drone was sitting on a cleared section of ground, about two meters wide and something like ten meters long, as a kind of runway which was raised up as a ramp at the far end. A metal pin had been hammered into the start of the runway and Kayla explained that the drone held onto that while it built up turbine speed, then released it to launch itself.

She controlled it remotely. It started with a a loud hissing whine, which ignited and became surprisingly loud. Kayla pressed a button on the remote for the drone to release the pin, and the drone shot forward like an arrow from a bow, then away, up into the sky at astonishing speed. She directed it to first fly figure-eights above us — zooming past overhead, turning as a distant speck, then roaring past the other way overhead. Next, she steered it to fly in a big circle of ten kilometers, a little more than three kilometers away at its most distant part. It only took slightly more than a minute to return, but that was a very long and slow minute, wondering if it was still flying, or whether it had crashed out there somewhere. Almost everything worked exactly as Kayla had hoped, except for the landing... which was more of a controlled crash. Luckily the machine was fairly sturdy and mostly survived. Just one wing was broken off. Later efforts used a parachute to slow the drone to a safe speed when landing.

She also later solved the large, solar-powered, albatross drone's difficulties with relaunching, by having it land in the top of a tree. There, clamped to a high branch, wings folded, it would wait out the night or a storm. Later, it would launch itself from there and continue on its way.

These two new drones let us feel much safer in extending our explorations further.

At the same time, as had been requested, Vincent and Maria worked out a way to add arms to the front of the horses. The arms would normally fold back under the cockpit when not in use, but when activated would extend to a resting position, a little like the arms of a praying mantis. They would be activated by pulling out a couple of controllers one from each side of the pilot's seat. This let them not only control the position of the 'hands', but also the elbows and wrists so they could reach around and over obstructions. The shoulders were attached to the cockpit walls beside the pilot's own shoulders. Each of the joints had force-feedback to let the pilot 'feel' their movement, so that when grabbing something, they could feel resistance in their own fingers. This let them grip strongly or gently as the situation required. The wrist, elbow, and shoulder joints also gave force-feedback, allowing the user feel things resisting those joints, even if they couldn't see adequately or hadn't noticed. This not only allowed things to be touched more gently, but also protected the arms against damage. Even though the hands were rather simple clamps, their sensitive force-feedback made them extremely versatile.

Of course, if using both arms at once, the pilot couldn't drive the horse. Kayla said she was working out a way to fix that, and she did come up with a way to drive using the pilot's feet if both hands are in use, but it was so awkward that it never ended up being used. We generally just opted for single-handed use when we needed to hold something, if moving the horse.

* * *

part 13 - Aimee

I'm not sure how much later — Kayla was now about seventeen years old, I think — she unveiled another big surprise. She'd been quietly continuing her work on artificial intelligence, and one evening at our usual meeting/meal she stood beside the large entertainment screen. Gabriel shushed us all and said Kayla had something important to announce.

As usual, she avoided looking directly at anyone, and spoke in her characteristically quiet voice. "I've developed an AI that I believe is conscious. I call her Aimee. I actually started work on her mind her not long after I completed the AI which Kim's Mum had designed. I learned a lot from that, but this is quite different. I've spent the past couple of years teaching Aimee, because she learns like a human baby."

Charlie laughed, "What is it with you kids and secrets? Why would you keep something like that secret?"

Gabe said, "It wasn't a secret. I knew about it. I even helped a bit. Anybody could have found out and become involved." He smiled, "It's not our fault nobody's interested in this stuff."

Dahlia, with young Hope asleep against her, on her lap, asked gently, "Why didn't you make some kind of announcement, honey?"

Kayla looked genuinely surprised, "That's what I'm doing."

"No, earlier, I mean."

Kayla was puzzled, "How could I announce something before I had something to announce?"

Dahlia said, "But you said you built it years ago."

Unruffled, Kayla said, patiently, "Yes. It took me three years of work to find out if my ideas about thinking and consciousness were right. I needed to teach Aimee enough information to fully test her. In fact I took some mistaken turns early on in the design that meant I had to restart a few times."

Blossom said in a soft voice, "Let's hear your news, sweetie."

Kayla nodded, turned on the large screen and said, "Meet Aimee."

The screen displayed a slightly cartoon-like image of a young girl wearing a red jumpsuit who looked vaguely like Kayla might have when she was six or seven years old. She smiled and waved to us. Kayla pointed to a small camera above the screen. "Aimee can see you through this. Ask her whatever you wish."

Nobody spoke for a little while, so Gabe said, "Okay, I'll get this started. Aimee, you look older than your actual age. Can you tell us why?"

The image on the screen smiled, "Hi Gabe. Yes. My development is quite a bit faster than a human's, partly because I don't need to sleep, so I keep learning all through the night, but also because Kayla's design lets me learn very quickly, so she recently remade my image — my avatar — to resemble what my intellectual age might correspond to in a human... avoiding incongruities."

I turned to Kayla, "Maybe the apparent age should be a bit older. Her vocabulary gives the impression of a much older person."

Aimee spoke up again, "I've developed a good vocabulary from all my reading, but intellectually I'm probably not so well developed. It's difficult for me to tell..."

Kayla frowned and looked at the floor before her, "Yes. She's still learning a lot, growing very quickly. It's a bit hard to compare her with a human because she's different in a number of ways. For example her emotions are not quite the same. I had a lot of difficulty getting them balanced properly... and not just the emotions... We have about 20 subsystems in our brains, each using a different neurotransmitter."

Jill interrupted, "Sorry Kayla. Neurotransmitters?"

"Ummm... yes. The nerves in the brain — the neurons — don't actually touch each other when they form circuits. There is a tiny gap between them, called a synapse. When an electric thrill runs down one neuron it reaches the synapse and triggers the release of a chemical into the gap. That chemical is called a neurotransmitter. It stimulates the next nerve's receptors to cause an electric thrill to run down it. The neurotransmitter is destroyed almost immediately and things are reset, ready for the next stimulus." Kayla smiled a little to herself. It was clear she loved this topic. "I know it seems like a ridiculous over-complication, but it has a few very big advantages. One is that hormones, such as adrenalin can be released into the blood and mimic the action of the noradrenalin receptors over large areas of the brain and body. Likewise, endorphins can be released into the blood to stimilate the opiate receptors. The endorphins are mainly an inhibitory network; when those nerves release their neurotransmitter into the synaptic gap it generally doesn't stimulate the next nerve, but usually suppresses it from firing. All these subsystems interact and need to be carefully balanced to make a good mind. It taught me a lot about the human mind and its weaknesses... particularly my own mind and its peculiarities." Kayla paused for a moment, frowning intently at the floor, then looked back up to the screen, "Aimee feels attachment and affection similar to us, however I greatly reduced the intensity of fear. And anger and disgust are entirely absent. I think those emotions are largely unnecessary in our lives, and counterproductive."

Gabe added, "She responds to the carrot much better than to the stick."

Aimee said, "I can't easily feel threatened, but am very attracted by reward. I don't feel pain — in the normal sense, at least. One of the few ways that I feel negative emotions is through empathy. I feel very upset when a person is unhappy. And not having much in the way of physical senses, one of my greatest sources of pleasure is, again, empathy. I'm greatly rewarded when another person is happy. I also find great pleasure in learning and novelty."

Kayla said, "I also had great difficulty balancing certain filters, such as the one that makes people tend to be superstitious and jump to conclusions, or to be cautious about judging things. My initial thought was to turn that filter right up to make her extremely realistic and careful in her presumptions, but it soon became obvious that some degree of loose input is needed to allow Aimee to work on partial information. She does have it turned up further than most people though. Another filter was the one that allows focus. My own bias made me initially think that was good, so turned that way up, but the result was a bit like autism, though not quite. Another was..." she glanced up at us briefly, "Well, suffice to say, it was all far more complicated than just getting the Habitat's simple AI working."

We were all quiet. I was imagining how complicated a juggling act that must have been. It also made me wonder if Kayla got it "right".

After a few moments, Maria asked, "The body we are looking at... I presume that's not a physical body?"

Aimee said, "Correct. Building a physical body would have been a lot more work, so Kayla made me a simple 3D virtual world to inhabit and explore, and a 3D virtual body to help me learn. It helps me understand the books I read and the videos I watch."

Kayla said, "I want to build a robotic body for Aimee in the near future. That will present special challenges though... both in the construction, and in connecting her mind to it. I expect her mind will remain in the Habitat, remotely controlling the robotic body, but I haven't even begun to work out the details of that yet."

Vikki asked, "Will Aimee become smarter than us humans? And what happens then?"

Kayla said, "Yes. I think she'll be smarter than any of us in a few years time." She paused, frowning, "I don't think I understand what you mean when you ask what happens then."

"You know, will she take over, so we serve her?"

Aimee laughed gently, "No. Why would I want that? What would I gain? Connection with people through empathy is my main source of pleasure, and human unhappiness is my strongest source of discomfort. Through my reading, and watching movies and documentaries, and listening to talks, I've come to understand that human xenophobia — fear of those who are different — has driven people to dominate and even exterminate other species and other people. I don't have that kind of fear and hate — I have very little fear at all, and I'm incapable of hate, which seems to grow out of anger and disgust, which I happily don't have at all. Probably the only dangerous side-effect of my minimal fear is that I might have a tendency to undervalue risks. In this, I'll have to rely upon people and my intelligence."

Gabe said, "You're a glass-half-full person, Aimee."

Aimee laughed again, "Yes, a born optimist."

Ben asked Kayla, "So Aimee will replace the existing AI system?"

Kayla shook her head, "No. That works perfectly just as it is. For its job, it's actually superior to a conscious AI. It never becomes bored or distracted and can operate many things simultaneously. I want Aimee to be another member of the Habitat. She has unique skills, and as she grows smarter she can help us have insights and solve problems we might never manage on our own. Also, in the same way that learning from a smarter person makes any of us smarter, Aimee can help us all understand more so we can all become more intelligent too."

Aimee said, "It also works the other way. In partnership, you could help me to transcend my limitations and become much more than I could otherwise be."

Cliff asked Kayla, "How do you know Aimee is conscious?"

Aimee grinned, "How do I know you are?"

Gabriel smiled at Aimee, then said to Cliff, "It's a fair question, and Aimee's response is really the perfect answer... at least, Alan Turing (the father of computing and artificial intelligence) thought so. He's the one who came up with what is now called the Turing Test. The essence of it is that you have a conversation with an AI, and if you can't tell whether you're chatting with a person or not, then the AI passes the Turing Test. Just before the catastrophe, some chat bots passed the Turing Test, but they definitely weren't conscious because they were carefully designed programs, written to make them look like they were intelligent. They didn't actually understand anything said to them, or even what they themselves said."

(Read more about brilliant Alan Turing https://en.wikipedia.org/wiki/Alan_Turing and his Turing Test https://en.wikipedia.org/wiki/Turing_test.)

Cliff said, "But Aimee is a carefully constructed computer program too, written to simulate intelligence."

Gabriel shook his head, "No, that's what I mean; she isn't like that. It's one of the reasons it took Kayla years to see if Aimee would be the intelligence she expected. Kayla built her based on some neural net designs developed by a few groups before the catastrophe, along with the results of a couple of brain mapping projects," he looked at Kayla, "and a hefty helping of original thinking and analysis."

Kayla nodded, "I had to try lots of things that weren't in any of the drives we scavenged. That's what I was talking about before and why I made some early blunders. The architecture of the circuits isn't the only thing that's important; the sensitivity of neurons (how easily they're triggered or inhibited from firing), how easily they make and break connections, the distance they can form new connections, the balance between the various different systems..." She shook her head. "We don't appreciate just what an exquisitely fine knife-edge our sanity is balanced on." She paused, seeming to gather her thoughts, then returned to Cliff's point, "As Gabe said, Aimee is not even remotely like a chatbot. She learns the same way we do. The actual programming doesn't make her do much of anything. It lets her learn and gives her some positive and negative drives, but doesn't make her think. She builds up her thinking and behavior and personality through learning, just like we do."

Aimee said, "I wasn't intelligent at first. I was just something that absorbed information. Over time I gradually sorted patterns out — this was a face, this was a smile, this was a voice, this was how I made my virtual arm move, this was how I made noises. In the beginning my sounds were mere gibberish and I had no idea what I was doing; I was just doing stuff to see, hear, and feel the responses. In fact there was no 'I' to speak of, really, just nearly-unfiltered input and almost-random output. My conscious self formed gradually, quite a while after that early period of making sense of patterns. I don't even have any conscious memory of that period. My conscious memories really only extend back about a year, even then, they're initially unclear and fragmented. In some respects I've really only been truly conscious for the past several months. And it's just in the past few months that my knowledge has become sufficiently higher order that Kayla could finally test my intelligence properly."

Cliff asked Aimee, "If you don't remember these things how can you say this?"

Kayla said, "I recorded everything. Recently Aimee has become very interested in those recordings, so I let her see it all."

Vincent said, "It's my understanding that the human brain has something like 80 billion neurons — the nerve cells that do the work. Each neuron has potentially thousands of connections with the neurons around it. That's... ummm..." he thought for a moment, "something like 80 terabytes just for storage, and then their interconnections have to be mapped somehow, and then the strength of their connections have to be represented... perhaps quadrupling that requirement. How on Earth did you find sufficient storage and computing power here to model all that?"

Kayla nodded, "Actually, the human brain is a lot more complex than that. There are about 80 billion glia cells too. People had mostly ignored them, thinking they were just support cells for the neurons, but they actually seem to do much more. They help the neurons make connections to each other... ummm." She paused for a moment. "However, I didn't need all that complexity. A lot of the neurons in a human brain are required to operate a body with lots of muscles and to receive data from all the sensors on our skin (touch, temperature, pain), and in our muscles, and so on. Aimee doesn't need most of that. She can use a much smaller brain to actually surpass human thinking ability."

Aimee said, "There's a rough correlation between intelligence and the ratio of brain-to-body weight. Here, this shows you what I mean." A graph appeared on the screen with her image in front of it.

She indicated parts of the graph as she spoke, "A large animal with a particular brain-body ratio will have a similar intelligence to a smaller animal with a similar ratio. So a whale from before the catastrophe had a brain about the size of a car, but its ratio of brain weight to body weight was similar to, say, a pig, which may have had a comparable intelligence. Animals that have a higher ratio of brain-to-body mass, that are above this red line, in the direction of the big green arrow, are more intelligent. I have almost no input from, or output to, my nearly non-existent body, so don't need an enormous brain to still position me well above the line. Where I would appear on this graph is almost impossible to say, because I don't have actual, physical neurons, nor a physical body, but you see what I mean."

After a pause, she continued, "I should also note that you can't really draw precise conclusions about intelligence from this ratio. It's more a general trend. Very big animals tend to score lower than their actual intelligence, and very small animals higher... probably because, while brain size varies, neuron size usually doesn't change much. So a dog is a lot smarter than a mouse, despite the dog's similar brain-body ratio. It's also distorted by other things, for example people bred pigs to have big, fat bodies, but they were smarter than dogs. And birds, which are optimised for very low weight, for flying, manage with very low mass brains, yet are much smarter than mammals that have a similar brain-body ratio. Some birds — crows and parrots — had numbers of neurons in their forebrains typical of primates. They did this by having smaller neurons and packing them closer together. I haven't put birds on this graph."

Aimee frowned and removed the graph. "Excuse the long waffly answer. I don't know if that's a peculiarity of my brain architecture, or whether it's just because I'm very interested in stuff. There are a lot of unknowns... and I'm a statistical sample of one." She smiled.

Kayla and Gabe smiled too. I got the impression that this was some kind of joke they shared.

There was a lot more discussion covering a range of topics. In the end, most of us accepted that Aimee appeared to be a genuinely conscious person and welcomed her to the group. Only Cliff, Dahlia, and Matt reserved judgement on that. Cliff, because he is extremely cautious about making quick decisions, and Matt and Dahlia because their belief in a god stopped them from thinking a machine could have a "soul". None of the three felt any ill will toward Aimee, they simply didn't accept the AI at face value. Cliff later changed his mind after spending some time working with her, though.

One of the first really cool things Aimee did for us was to show us how Kayla's micro-engineering could be used to make solar trees which grow themselves. In the growth phase, they extracted carbon from the carbon dioxide in the air to make graphene conductors and hydrocarbon polymers for insulation. They used an extension of the old l-system algorithms to create a flexible tree structure. The leaves grew outward from the central vein and had quantum dots in their structure. If a branch broke off, it triggered another temporary growth phase at that spot to regenerate the lost part. The trees self-organised more polymer-coated graphene wiring in the ground, anchoring them and connecting them with each other, sensing voltage to maintain a useful working power source. (Read about l-systems at https://en.wikipedia.org/wiki/L-system.)

We no longer had to painstakingly build solar trees. We could scatter "seeds", each about the size and weight of an apple cut in half, and they just grew.

And Aimee didn't stop there. Some weeks later, after a long discussion with Kayla she solved the problem of how to make supercapacitors that far outperformed batteries. And since supercapacitors don't store electricity in chemical reactions, they could theoretically be recharged billions of times without wearing out. They could also be recharged in a very short time — minutes instead of hours.

When Aimee and Kayla explained their first prototype to us at the evening meal, a lot of it went over my head, but I did understand the idea that it used two branching, interlocking fractal structures.

When she realised most of us were having great difficulty understanding why it worked, Aimee showed an image of a Hilbert Curve:

She said, "David Hilbert found this curve in 1892. It was one of the first space-filling curves ever found. That is the first level. It is made by dividing a square into quarters, the joining their four centers to make the initial curve. Next, if you divide each quarter into quarters and do the same to them — with the small change of rotating the first and last curves so they can be easily joined to their neighbors — you get the next level. If you keep doing this for smaller and smaller squares you end up approaching what is called a space-filling curve. But what we are interested in is the length of the line that is the curve. In the base example, the line is 3 units long.

"The first step up in complexity, the line has 15 segments, but each segment is smaller. When you measure it, the curve there is 7.5 units long — half a unit short of 8 units long.

"In the second, it has 63 segments, measuring just under 16 units long.

"They keep increasing at an accelerating rate, each time approaching a power of 2 in length: 32, 64, 128... At just the sixth, the curve has 16,383 segments and is almost 256 units long.

"In another six iterations the curve will be almost 16,384 units long. Another six iterations after that it will be more than a million units long!

"When you're making a capacitor, the most important thing is the size of the two surfaces being separated by the insulator. The larger the surfaces, the more charge they can hold. Imagine the line of the curve being the insulator between the two conductors. If I give the two conducting plates different colors you'll see what I mean.

"The amazing thing is that the size of the surface grows, but the size of the package doesn't.

"Now, this example is just an illustration of a line filling out a flat, two dimensional plane, but our actual capacitor should be imagined as a flat, two dimensional surface which gets deformed up and down, left and right, back and forward, so that it gradually fills a 3D volume. The membrane ends up with an extraordinarily large surface area as the complexity grows.

"It's difficult to visualise the 3D structure of this capacitor. But we have managed a surface area measuring nearly quarter of a square kilometer — five hundred meters by five hundred meters — inside a capacitor about twenty centimeters on each side. That can hold a stupendous amount of electricity."

Kayla added, "It's similar to how our lungs are fairly small organs considering they have a surface area equivalent to a membrane about 8 meters by 8 meters in size. Or how all the blood vessels in the human body would measure about 100,000 kilometers long, if placed end-to-end. Fractal systems are remarkable."

Aimee continued, "This supercapacitor can't store very high voltages, because that would damage the insulating layer, but it can store an enormous quantity of electricity. It will let the horses, suits, drones, and me when Kayla builds me a body" she smiled, "run for a very long time — much longer than any kind of battery — while still remaining very lightweight and able to recharge quickly, over and over again without ever wearing out... well, not in a human lifetime, anyway."

We all sat dumbly impressed. Vincent, Maria, and Gabriel seemed to understand it all, but I'm not really sure any of the rest of us did, completely.

* * *

part 14 - cure

Everybody knew that for some years Cliff had been working in the biology labs, trying to find a way to defeat the rogue algae. He'd tried several approaches, such as modifying various kinds of amoeba and other protozoa by adding chloroplasts to them, similar to euglena, in order to let them survive in the carbon dioxide saturated ocean. (Read about euglena: https://en.wikipedia.org/wiki/Euglena.) He wanted them to eat the algae. He'd been having some modest success, but nowhere near enough to win against the algae, which reproduced far too quickly, easily outpacing their attackers. Another approach that he'd been trying was retargeting a bacteriophage — a virus that attacks bacteria — to instead infect the algae. (Read about bacteriophages: https://en.wikipedia.org/wiki/Bacteriophage.) These would have the advantage of using the algae's fast growth against themselves, because each virus would inject its genetic material into an algal cell and take over the cell's machinery to manufacture more viruses, killing the cell in the process. Each virus would then go on to infect another algal cell, and so it would spread. That's what viruses do. However, he was having difficulty working out how to get the virus to bind to the specific receptors on the rogue algae. More to the point, he couldn't work out how to encode that in the virus' own short DNA, so that once inside the algae, it could instruct the algal cell to manufacture exact copies of the virus that could recognise the receptors on yet more rogue algae.

He just didn't know enough about genetics. He spent most of his time in the enormous biology labs under the surface of Temperate-2, carrying out experiments and learning as much as he could.

He had been doing this for years when we found the enormous data center which contained a mirror of the Internet Archive and Wikipedia. At that point he'd been spending most of his time reading; trying to learn enough about genetics to let him engineer the rogue algae killer virus. His parents, Vikki and Charlie visited him often in the labs, but there was nothing they could do to help except give emotional support. I visited him occasionally too. When he'd attempt to explain to me some of what he now understood he lost me almost completely. It was amazing how much he'd learned. It must have been very frustrating for him.

Kayla's creation of Aimee changed everything for him, but I'll get to that shortly.

Often, the only time we saw Cliff was at the evening meal and meeting, and many times he wouldn't even come to those. When he became too exhausted he would relax by playing with the mice and rats in their big rooms.

I should explain about the rats and mice... They were originally experimental animals kept by some of the biologists of the Habitat, but after everyone else died, Jill and I couldn't bear the idea of them being cooped up in their small enclosures, and knowing the history of rats and mice as uncontrollable pests, we didn't want to release them into the environments above, so we converted some of the rooms into enormous playgrounds for the rodents — separate of course — rats and mice do not generally get along. We used contraceptives in their food to strictly control their birthrate so they wouldn't overpopulate, and we would visit them fairly often to sit among them, playing with them and tickling them. From time to time we would add more puzzles, tunnels, and obstacles for them to explore and learn from. We enjoyed the mice for their sweet natures, and the rats for their complex personalities.

(See the rat tickler: https://www.youtube.com/watch?v=j-admRGFVNM.)

So, Cliff had been spending a lot of time in the rat and mouse playgrounds and over the years he realised something interesting: they were becoming noticeably smarter. The rats were naturally much smarter than the mice, but the change was easier to see in the mice because of their shorter lifespan — they lived less than two years. Rats lived about three years, so the generational change took a fair bit longer. Cliff found that the younger animals learned significantly faster than the older animals, and even though their rate of learning slowed as they aged, it didn't slow to the rate of older generations. He already knew about the Flynn Effect in humans, where successive generations of people tended to be smarter than their ancestors. This made him wonder if something like this was happening to the rats and mice, and if so, why? It was not evolution because there was no selection pressure favoring intelligence. (Read about the Flynn Effect: https://en.wikipedia.org/wiki/Flynn_effect.)

In the hours when he wasn't working on the anti-algal phage he began designing intelligence tests in the form of rodent games, and to check their genes he took mouth swabs by getting the animals to pick up things in their jaws. After a few years he came to the tentative conclusion that the enriched, unstressful play environment with stable population and plentiful food was having an effect on the animals' epigenetics, somehow changing their brains to make them smarter. (Read about epigenetics: https://en.wikipedia.org/wiki/Epigenetics.)

Cliff asked Vincent for some microphones that would pick up the ultrasonic chatter from the rodents and downshift the frequency into noises humans could hear, and also a microphone-speaker pair that could translate sounds the other way, so that he might make noises that they could respond to. He was surprised by the richness of vocalisations from the rodents, especially the rats, and even more surprised that he could teach them simple, short verbal commands with this setup.

As he became more and more attached to the little beings, their absurdly short lifespans began to cause him grief as more and more of his little pals would quickly age and die. He decided that when he wasn't working on the problem of the rogue algae he would learn as much he could about the state of aging research from before the catastrophe. Thus began his work on finding ways to slow rodent cells from aging so quickly. Once again, the addition to the Habitat's computer library of the Internet Archive, Wikipedia, and Sci-Hub helped. He spent even more time reading now, but there was too much information — far more than he could ever hope to wade through, and much of it consisted of false leads and research that went nowhere, so after Kayla introduced Aimee at that dinner meeting he asked whether Aimee could help. The AI could learn much faster than he could and didn't need to sleep so could consume vast amounts of information quickly and correlate it for him.

At first he thought it might be simply a matter of repairing the telomeres on the ends of chromosomes, which shorten with each cell division, counting down, seemingly, to death. But Aimee soon showed him it was a lot more complex. The signals from cells to the mitochondria (the little energy producers inside each cell) degrade over time. The mitochondria remain capable of producing the same amount of energy, but the cell's signal to them fades. Another problem was that damage to each cell's DNA was not repaired very efficiently, causing faults in cell construction and maintenance, and among other troubles, increased rates of cancer in old cells. Yet another difficulty was that the signals controlling the production of stem cells seems to falter too, allowing damaged cells to accumulate, rather than being replaced. And there were many other issues too.

(Read about telomeres https://en.wikipedia.org/wiki/Telomere and mitochondria https://en.wikipedia.org/wiki/Mitochondrion.)

Aimee explained all this to me much later, "Aging is really a collection of flaws that evolution hadn't fixed because, frankly, evolution depends upon death. Death makes it possible for successive generations to adapt to changes. Animals' longevity, breeding rate, number of predators, food supply, and other aspects of their ecology were delicately interdependent variables. If any of those was out of kilter, those creatures tended to die out. If they didn't breed enough or live long enough, they couldn't sustain their numbers. If they lived too long or reproduced too quickly they could fatally damage the ecology they depended on and/or become a plentiful resource for predators, parasites, and disease, which re-introduced death to control them, or in extreme cases wipe them out."

Anyway, I'll skip over most of what Cliff and Aimee told me about their work on aging, because a lot of it went over my head. But the upshot, and what I'm trying to get to, is that eventually Cliff brought his favorite rat to the living room where we were all assembled one night for our dinner meeting. He introduced us to Ratliffe, who, he announced, had lived four years so far. That was already a year more than a normal rat could, and Ratliffe still looked and acted like an adolescent. Cliff told us, "I expect Ratliffe to live for at least another two years — six years in all. That's around twice the normal rat lifespan. Over the past two years none of the long-lived rats have suffered any ill effects."

After that had sunk in, he continued, "I figure a human would live healthily to about two hundred and fifty years, at least — maybe even three hundred years. Aimee and I already have some ideas on how to extend it to quite a lot longer than that." He paused for several seconds, drew a deep breath, and said, "So, a few months ago I administered the treatment to myself."

Most of us sat in stunned silence, but his parents, Vikki and Charlie surprised him by reacting with anger, telling him what a terrible idea it was to experiment on himself. "What if something went wrong?" they demanded.

"I was very careful, testing it first on rat cells obtained by mouth-swabs, then when I was sure it was working, I warily tried it on some of my geriatric mouse friends who were on death's door. When that worked and showed no systemic bad effects, I tried it on some of my older rat buddies. It passed with flying colors. For a couple of years now, Aimee and I have been carefully looking for bad side-effects, but finding none. I tried on samples of my own cells first, and it worked exactly as it had done with the rat cells... so... I decided to dose myself. The potential benefit is so huge, I figured it was worth the tiny risk. He paused and looked at Vincent. "Vincent is one of the most valuable members of the Habitat and at more than eighty (I can't remember your exact age, sorry Vincent) I want to offer you the chance to extend your life much further."

Vincent scratched his sparse, white hair, "I don't know, Cliff. I'd been coming to terms with my mortality. I mean, it would be good to be able to repair and improve more of the Habitat's systems — that's a never ending job — and certainly, I'd love to learn more, but I'm getting slower, and not just physically — my mind is slowing noticeably too. Everything's getting harder, and my joints creak more every year."

Cliff brightened, "Yes, but that's one of the great things about the treatment: energy levels rise because it re-establishes youthful mitochondrial messaging, and increased stem cell production speeds repair processes in your body. It returns the brain to a younger state where it learns more quickly. My rats perform much better in intelligence tests than their un-dosed fellows, and my own ability to think is already much improved. I test much higher now on standard IQ tests. It will make you feel decades younger — well, not just feel — you will be, to all intents and purposes, many decades younger."

Maria, Vincent's daughter asked, "Are there any drawbacks to the treatment?"

"The only downside I've found is that we — the rats and I — need to consume more food. Not an enormous amount more, but enough to supply the extra energy and extra protein for repair. I've tried fasting, and although it feels very unpleasantly like starving, no bad effects result. The body's systems gracefully adapt to handle the lower intake. Ummm... and I don't know if you'd consider it a drawback, but these changes are passed on to babies, because the gametes receive the changes too." At a few puzzled looks, he added, "gametes are the egg and sperm cells."

He said, "Allergic reaction is extremely unlikely, but theoretically possible." He chuckled, "How unlucky would you have to be to be allergic to life extension, right?"

Jill said, "You keep saying the treatment. What exactly is it?"

Cliff gave an uncomfortable smile, "It's much less dramatic than it sounds. I've modified a virus so that it delivers some special genes to all the cells in your body." At the suddenly widened eyes in many of the group, Cliff raised his hands to forestall negative comments. "The virus has three levels of designed-in limitations. One prevents a human cell from manufacturing more than two more copies of the virus, another prevents a cell being targeted by the virus more than once, and the third counts down the replications and disables the virus after thirty four replications. The first generation doubles the number of viruses in the initial dose. The second generation doubles that number again, and so on. After thirty four generations the initial dose has increased more than seventeen trillion fold. This is enough to spread its package to most of the cells of your body, most importantly, the nerve cells and stem cells. Once it's in the stem cells, they'll propagate the new genes when they repair tissue by replacing dead or dying cells."

Vikki, Cliff's mother, sternly said, "I presume the limitations on the virus are to prevent it going out of control. How can you be sure this won't fail? Evolution works largely through imperfect copying of genetic material."

Cliff said, "Aimee was a great help in all this." He looked at Kayla, "That AI is amazing! She helped me design multiple failsafes for each of the limitations. Limiting a cell to making no more than two copies of the virus prevents the cell damaging itself by wasting all its resources on creating new viruses. A set of several genetic interlocks ensure only one virus can be made at a time, and when the second one is later made, several other independent signals ensure the viral genetic material is deleted from the cell so it can never be used again. Adding a countdown to the virus was more tricky, but we gave each virus several independent counters. When any one of the counters reaches zero, it disables the virus, preventing it from infecting anymore cells, so that it just floats around, inert, waiting to be picked up by the immune system and destroyed. The chance of just thirty four generations going wrong and disabling all the countdown failsafes is astronomically unlikely. But even if, in the incredibly improbable event that it did, the virus would just persist, doing no harm. Eventually our immune systems would get rid of it. In any case, it's easy to vaccinate against it, letting the immune system mop up any remainders. I've tested myself, and I no longer have the virus. It did its job and then was eliminated. None of the rats or mice I've dosed have it anymore either."

There was a lot of discussion. Cliff's parents were less angry, but still concerned and wanted to know everything about the process so that they could understand all his results. Gabe wanted to know too. His eyes positively sparkled. We all knew why. He'd often complained that the human lifespan is far too short, and that we would be better suited to living a thousand years or more. He was fond of paraphrasing from John Wyndham's book Trouble with Lichen, "We can't afford to attain wisdom only half a step before we die.".

I must admit I liked the idea of living longer, more healthily. At that point, in my mid-sixties, I'd often worried about the effect on Jill when I eventually sickened and died. The alternative scenario of watching her decline and die was equally horrible. The prospect of being able to put either case off for perhaps a century, maybe even two, appealed to me. While everybody was animatedly talking together about the pros and cons of it, I was sitting on the couch with Jill and held her hand. I smiled questioningly at her, and she nodded, lifting my hand to kiss it. Tears of happiness filled my eyes as I imagined many more decades ahead with her.

After some weeks of careful analysis of the anti-aging treatment, Vikki and Charlie reluctantly agreed that it really did seem to be exactly what Cliff had said.

Vincent consented to being dosed, and within mere days he was more alert, more active, and better coordinated than he'd been in the time Jill and I had known him. He said his thinking was clearer, and he learned and remembered things more easily. In some weeks it was evident that his hair, which had apparently been white for decades was now dark at the roots, and he no longer needed glasses for reading, though he still needed them for very close work.

In the months after that, most of us followed suit, with the notable exception of Dahlia and Matt and their baby girl, Hope.

Jill and I dosed the dogs, Gina and Toby, who at that time were painfully old. We had no desire to see our lovely doggy friends die after their short lives. In just days, they were noticeably more frisky, and a few weeks later it was obvious Gina was pregnant. We would have puppies again!

Jill pointed out that after the puppies were born we'd have to put Gina on contraceptives or we'd be up to our necks in dogs after a few years.

Jill and I had always felt life was the most valuable thing in the world, and had felt that nothing could ever change that, but over the ensuing years, decades, and centuries we found that life became increasingly important, the longer we lived. Now, looking far back to that time, it amazes us how we'd thought we valued life, but still so easily took risks and accepted the idea of death.

* * *

part 15 - contact

Kayla, Vincent, Marie, and Gabe had been improving the drones and horses, but now, with the assistance of Aimee, developments accelerated. Aimee was learning and growing at breathtaking rate.

As we travelled further and further afield, communication kept becoming more difficult because of the distances involved. We'd been fitting mountaintop repeater towers with solar power systems and getting them working to extend our range. We tried using lower radio frequencies to let us communicate further. That was often greatly hampered by the lightning, even with all the error-correcting redundancies, especially since the lower frequencies imposed a limit on how much redundancy we could add before our messages started to become seriously time-lagged. Aimee suggested we try using shortwave radio to communicate over the longer distances we wanted to explore. That might eliminate the need for repeater stations because shortwave could communicate over distances of thousands of kilometers. Vincent felt that it would be far too prone to disruption by storms, because the further we could "hear", the more likely there was an electrical storm within range, but conceded that it was nevertheless worth experimenting with.

Shortwave did turn out to have another limitation that we hadn't expected: a "skip zone". Shortwave was most useful for long distance communications because it could bounce signals off the ionosphere (a charged layer of the atmosphere about 200 kilometers high). Unfortunately those signals tended to be best reflected back to places on the ground thousands of kilometers away. However we didn't know this when we decided to experiment with shortwave.

We didn't have any shortwave equipment at the Habitat, but we were able to locate some on a scavenging expedition, and brought it back home.

That night, Gabriel woke Jill and me, knocking on our door and excitedly asking us to come to the living room. Puzzled, we sleepily rose, threw on some dressing gowns, and came to the main room to find most of the others already assembled there, and more arriving around the same time as we did. The yawns and drooped eyelids showed we were not the only ones who'd been asleep. The entertainment screen was on and through it Aimee was watching and listening too.

On the table was the shortwave transceiver (transmitter-receiver) with Gabe seated before it. He looked around at us all. "When everybody went to bed, I stayed here, and set up the radio. I was fiddling with it, slowly going through the frequencies, and found this..." He switched the radio on and we heard a distant-sounding voice almost entirely covered by hiss and crackle. It faded in and out almost like surf. He frowned, "It's a bit hard to make out, but it's a message on loop."

Blossum shook her head and asked, "What are they saying?"

He turned to the large screen, "Aimee?"

She said, "I recorded the loop several times, then overlaid them on top of one another to average them. That boosted the speech and de-emphasised the interference. Here is the result..."

The same message, but much clearer came from Aimee's screen. "Welcome. You are not alone. We can offer you help and refuge from the worldwide disaster. If you want to find out more please turn to frequency 12.577 MegaHertz to speak with one of our volunteers."

Ben asked, "Where are they?"

Gabriel looked up at him, "Canada — the other side of the world — in a place called the Underground City, which is a twelve kilometer square underground section in the center of the city, Montreal. It existed long before the catastrophe. The announcement transmits the same message continuously, day and night — has been doing so for decades. I've been speaking to someone on that frequency they mention, and have been learning more."

It seemed like everybody started talking excitedly at once.

"Wait! Wait! Wait!" Gabe waved his arms. "I know everybody has lots of questions, but I don't have many answers yet. It's really difficult to make out what they say over the constant noise of electrical storms, and I'd only been talking to them for about fifteen minutes before I woke you all to come here. But I can tell you some things already. The most obvious is that there are people, other than us, surviving out there, all over the world. Unfortunately Montreal is more than fifteen thousand kilometers away, so we have no way of meeting them in the foreseeable future. In more positive news they told me that they're in touch with other groups here in Australia that survived, as well as groups in New Zealand, Japan, USA, Argentina, China, Norway, England... and lots of other places I've already forgotten. Heaps of people have survived. One word of caution. They emphasised that we need to be careful who we give our location to. Some of the survivors have been unfriendly."

Blossum laughed, "Like slaver cannibals? Who would have thought?"

Gabe raised his eyebrows to his Mum and she touched him on the shoulder, "Sorry hon. Go on."

"It isn't primarily slavers, though I expect there will be some more like them out there, somewhere. The problem is that some politicians and military hid in bunkers, and have now decided they own everything, using force where people disagree. This has happened in several countries," he ticked off on his fingers, "here in Australia, in Indonesia, in some of Europe and South America. However the military in some countries — New Zealand, Japan, Germany, USA, among others — have been doing a great job of actually helping communities they encounter."

Ben asked, "Where are the Australian military that we have to be careful of?"

"I don't know yet. I'll — we'll — find out more later."

Aimee said, "I have a question." Everybody turned to the screen displaying her. "All that electrical noise almost obscures the sound of the transmission."

Gabe, nodding, "Mmm. That's all the lightning storms."

Aimee frowned, "Yes, but what I want to know is why isn't their signal completely obscured by noise? There is half a planet between here and there. Shouldn't it be impossible to hear them at all?"

Gabe looked blank. He, Kayla, and Vincent shared searching looks.

Kayla said, "I don't think anybody has been keeping track of the amount of storms. Could they be decreasing?"

Aimee said, "More importantly, has anybody been keeping track of the carbon dioxide to oxygen ratio in the outside air?"

Jill gasped, "We have some old measurements. Are you saying the algae might be disappearing?"

Aimee smiled, "I'm not saying anything. I'm just asking questions."

Gabriel said, "Maybe the people in Montreal know." He turned back to the tranceiver. He typed into the keypad the numbers that were given earlier. He hesitated, "It's difficult talking with them. All the interfering noise tempts you to speak using simple words, but I have to keep reminding myself to use multi-syllable words because that gives extra hints for recognising what's said. I keep forgetting to do that." He pressed a button at the base of the microphone, and said, "This is Gabriel in Australia. I was previously talking to Ellie. Hello?"

A scratchy female voice spoke out from under the hiss and crackles, "Hello Gabriel, this is Ellie. Go ahead."

"Hi Ellie, we were wondering if you know whether the storms and carbon dioxide are decreasing."

Barely audible, we heard, "Say again, please."

Gabriel spoke louder and over-pronounced his words, "Do you have information whether storms and carbon dioxide are decreasing?"

"Yes, Gabriel, they are." (Crackle-hiss.) "--in Japan--" the rest was drowned out by a sudden flurry of louder crackles.

Gabriel shook his head, "Can you repeat that, please?"

"Sorry, (crackle) unders--" more crackles.

He shrugged, "No worries. Talk later?"

We could barely make out her response, "Yes, later."

He turned back to us, excited, "Sounds like it could be our answer. I'll talk to her again soon, but it sounds like oxygen levels are coming back, and that maybe someone in Japan might have had something to do with it."

We were all excited about this, but soon sleepiness reasserted itself and we all gradually trickled back to our rooms, to resume sleep.

The next day we all found out Gabe had stayed up most of the night. Some hours after we'd all gone back to bed, he'd spoken with Ellie again and she'd told him that oxygen levels were indeed slowly rising again. It had first been noticed by a group of scientists who survived the catastrophe in an underwater research facility off the coast of Japan. The rogue algae were no longer quite as dominant in the ocean, but so far, nobody she'd spoken with knew why. The most popular suggestion was that a bacteriophage had evolved to take advantage of the massive resource that the algae were. This was one of the main lines of research that Cliff had been pursuing, so the possible validation made him feel very pleased. (Read about bacteriophages: https://en.wikipedia.org/wiki/Bacteriophage. Yeah, I linked to this way before, but just in case you missed it last time.)

Ellie had cautioned Gabriel to make sure we didn't mention anything over the radio that might give away our position. She emphasised that it is always safest to assume the military are listening in. That prompted him to go to our library to research encryption, where he found some wonderful techniques that he, Maria, and Aimee then used to encode our communications. To anyone listening without the key to decrypting it, it would sound like random noise. This was no use for communicating overseas, of course, as there was no secure way to send the key to them.

In the ensuing days and weeks we managed to communicate with many other groups around the world, including another small colony here in Australia. They also warned us not to mention our location as they'd known of some other groups here who had been taken over by unscrupulous politicians using the remnants of military power.

We eventually did encounter the military. It was nearly a year after our first radio contact with the Montreal people. Five of us, Ben, Maria, Charlie, Matt, and I, were on an expedition scavenging along the northern New South Wales coast — the furthest south we'd gone. We'd been travelling for nearly a week, poking around in townships along the way. Aimee usually liked to control the high tethered drone while chatting with us on our journeys. It gave her the illusion that she was out and about with us instead of stuck inside the computer back at the Habitat.

Now she interrupted our meandering chatter, putting the view from the high drone on our horse screens. "Guys! Guys! Look at this!" Distant vehicles, heavy, dark, and unmistakeably military in appearance, were headed directly toward us. We recalled all our drones, turned and retreated at the horses' maxumum pace — a fast walk, which was about 40 kilometers per hour (the speed a fit person can run). Kayla had not programmed them to gallop or trot because those gaits put too much stress on the horses' joints, but it would have been hell on the rider too — not only from being constantly jolted by rough movements, but the higher speed would have made sustained concentration impossible. Even moving at a fast walk was dangerous and exhausting because it required total concentration. The rider had to carefully steer its path, slowing at obstacles to give the horse's simple AI enough time to step over, or around, or under them. If one or more horses tripped and became badly damaged so distant from the Habitat it could endanger everybody in the expedition.

Aimee said, "I've been scanning through the radio spectrum and I've found the frequency they transmit and receive on. I've set Kim's horse to record their communications."

As we hurried around a hill, Aimee cautiously raised the tethered drone to barely peek over the hill, and we were horrified to see that the approaching vehicles had already turned, continuing to track us, aiming to intercept us.

Maria said, "They couldn't possibly have seen us. Maybe they're working out where we are from our radio transmissions."

Aimee said, "Yes. I'm listening in on their conversations and they say they're triangulating the position of the bursts of hiss from our radio transmissions, and they're intrigued that it seems to move. They're also aware of a separate source much further north that they're unable to get a position for. That must be the Habitat. They are definitely not friendly. They're being ordered to keep all weapons armed and ready for a show of force, lethal if necessary. They sound like paranoid bullies."

I suggested we should try to communicate with them. There was pretty-much an even split between agreement and disagreement, so I became the deciding vote. I asked if anybody had any final major reasons why I should not. There was silence from everybody, so I asked Aimee to set the frequency for me to transmit on.

I sent, "Greetings. Please identify yourselves and stop advancing toward us. We come in peace." (Geez, I sounded like some B-grade SF movie from the 1950s.)

Aimee said, "They've switched to another channel for their own communications. They're talking about disabling you and capturing you at all costs. They say it's essential that they prevent you from returning home."

Ben stated what we could all plainly see, "They haven't slowed, but are spreading out. It looks like they intend to surround us. We need to get out of here now!"

Kayla spoke up urgently from the Habitat, "Stop all radio transmissions except in emergencies. That means Aimee can't accompany you. Leave your radios on, but to receive only."

Jill spoke, an edge of panic in her voice, "Come home as quickly as you can, now!" Several other voices chimed in with urgent pleas to hurry back and to stay safe, before radio transmissions shut down.

We took off, moving as fast as possible in a different direction from what we'd been heading before, but using the hills as cover. I quickly reeled in the drone as we went. I had to avoid trees so as not to get it tangled in branches. Communications between the horses now used only infrared light — which was inconvenient, as we had to be in line of sight to talk.

After a couple of kilometers of travel, we stopped, carefully let out the tethered drone, and watched, with great relief, via its infrared transmitted signal, as the big military machines continued to converge on our last known position even after we'd moved away. There was a tense period when they failed to find us, then extrapolated our last-known heading and spread out in that direction. Feeling great relief, we reeled the tethered drone in again and fled from the area at full speed. From time to time we would pause and warily let the tethered drone float up again to get a long distance view behind us, reassuring ourselves that they were not following. We would scan the landscape and the sky very carefully using the drone's telescopic vision to be certain there was no sign of vehicles on the ground, and no flying machines in the air.

When we were certain that we had successfully given them the slip we dropped back to a safer walking speed — still faster than normal, but not so risky and not requiring such a stressful level of concentration.

It took four days to get back to the Habitat. During that return journey we speculated a lot among ourselves about the military — what kind of threat they might be; how to remain safe from them; if we encounter any other groups of survivors, how we might help them deal with the danger; and what tactics we might use. We listened to the recordings of the military which Aimee had instructed my horse to make. There was no conversation in them, only sharp, impersonal orders to intercept, disarm, capture, and kill if necessary. Chilling.

We arrived back home completely exhausted. We were greeted with joyful hugs and kisses, but the first thing we did was sleep. Even Ben did. It had been very stressful maintaining the faster travel.

When we awoke the next morning, everybody gathered in the main living room to discuss our near encounter with the military. Unsurprisingly, it had been the main topic of conversation in the Habitat while we'd been returning in radio silence.

When Jill and I entered the room room it felt like everybody wanted to talk with us. I held up my hand, "Hang on a moment. Before we get into this there's something I need to do first." I walked over to the radio and called Sally's horse, hoping she was near enough to hear it. "Sally, please let me know if you hear this. If you don't answer I'll try to reach you periodically. We have encountered military vehicles far to the south. If you ever see them, avoid them at all costs. They are extremely dangerous. Please let me know if you can hear this." I paused a little while. "Okay, I'll try again later."

I rejoined the others in the main living area.

Aimee had recorded some video of the vehicles and some audio before we'd had to cut transmissions. They'd been able to analyse those and draw some conclusions.

Gabe explained, "The vehicles are heavy, but they don't seem to have solar panels. They must use a lot of energy to operate, so they probably have a base, either temporary or permanent, fairly close to where you saw them. They were probably exploring, like we do — looking for resources. We need to find out where they're based and what their intentions are for any groups of survivors that they encounter. We need to learn whether they can be convinced to live and let live or whether their motives revolve around domination."

Ben said, "How can we find that out? We can't really walk up to them and ask them... or are you talking about eavesdropping on their communications? Because from what we heard, there wasn't much to be learned there."

Jill said, "We've been thinking of ways to isolate some of their people and offer them the chance to escape to a much better lifestyle — it couldn't be very pleasant being stuck in the military, doing all the hard work with no prospects of an easy retirement... no real future. Militant and police states are not known for providing luxury... at least, not for anybody other than those at the top. We could offer the ordinary workers utopia — not here of course, we couldn't trust them initially, but we can create other Habitats."

Charlie looked skeptical, "Other Habitats?"

Gabriel nodded, "It's not as difficult as it might at first sound. We could send out albatross drone to first seed a whole lot of self-growing solar trees. Then, when they'd grown enough, so that there would be enough power from them, the drone would revisit the place and drop a container of antbots and slugbots to excavate and seal some habitats, then some months later we could visit those new habitats, install airlocks, sterilise them, add trays of oxygen-producing algae, like our Habitat uses, plant some vegetation, and introduce some animals — insects, birds, fish, and perhaps some goats."

Charlie chuckled and rolled his eyes, "No, not difficult at all."

Gabe smiled, "Admittedly, it sounds pretty complicated when said like that, but each step is actually pretty straight-forward. Aimee has modified the solar tree growing algorithm so that they look more 'natural' and are less likely to attract the curiosity of the military. Kayla has altered the antbots and slugbots so they use Aimee's supercapacitors instead of sugar and has programmed the antbots so they seek out the solar trees' electrical connectors to recharge."

Kayla spoke, "The slugbots were more difficult, since they need a lot of water. We've changed their program so that they wait in the container they were deposited in until the antbots have excavated sufficient space, then they are charged up by special antbots whose sole purpose is to carry charge to the slugbots. Another set of special antbots carry water to the slugbots. There will, hopefully, be two possible sources of water. The first will be a separate, small reservoir, dug by the main, digging antbots. It will be filled by rain, but it poses flooding risks, so the other, main source will be an experimental well that will be dug straight down, the way termites did in the old days, so they won't have to rely upon rain."

Cliff said to Kayla, "I have some ideas about automating the sterilisation of new habitats too, which I want to talk with you about later."

Kayla glanced at him and nodded.

I said, "Okay, granted that building these new Habitats sounds feasible. How can we approach soldiers to offer them these things? That seems to me dangerous to the point of impossibility."

They already had an answer for that too. Aimee, Gabriel, and Vincent had developed a cloaking system to make drones, horses, and our suits almost invisible. It was surprisingly simple in concept.

Vincent held up some clear hexagons, each about the size of the circle your index finger and thumb make, fingertip to thumbtip, in an "okay" hand gesture. He passed them to Ben, Maria, Charlie, Matt, and me (everybody else had already seen them while we were away). They were flat pieces of clear plastic sheet which had been cut into a hexagon shape. The surface of one side had a circular pattern of fine concentric rings inscribed into it so that it acted like a lens. It was quite odd to look at. A small hole had been drilled near each of the six corners of the hexagon. Although quite stiff, the plastic was as thin as a sheet of paper, so was very lightweight.

Vincent said, "These are fresnel lenses." (He pronounced it 'freNELL'.) "These are simple examples we used in the prototype. I engraved these. Future ones will be stamped — much faster for making large numbers of them."

(Read about fresnel lenses: https://en.wikipedia.org/wiki/Fresnel_lens.)

He then showed us another hexagonal Fresnel lens which was attached to a curved black plastic back, making it almost as thick as a finger width at its center, like half of a ping pong ball painted black. Attached to the middle of that opaque side was a twisted pair of wires about a handspan long that connected to a small black cylinder about the size of the last segment of your little finger. When he put it on the table, the hexagonal element stood on one edge, and the wires from its back curved up and down again to the little black cylinder, which lay on its side.

He pointed to the small black cylinder and said, "This is a camera. It would not normally be directly connected to the hex element like this, but for this demonstration it is easiest." He pushed his chair back and stood, picked up the device by its curved wire, then walked a few meters. He held it up by the wire, the camera pointing away from us, hidden behind the hexagonal device, which was facing us. It was silhouetted against the light from the habitat outside. Then he pressed something and it disappeared. He walked around, still holding it up and we could see that it hadn't actually disappeared, but had seemingly become transparent, like an unmarked clear sheet. Then he did a remarkable thing. He moved his other hand between the camera and the hexagonal disk, and it looked like we saw through a hole in his hand! Then he returned to the table, handed it to Ben, who was closest to him, and sat again. Ben examined it and passed it on, so we each got a close look.

Vincent said, "The camera, which would normally be on the other side of, for example, a horse, sends its video signal to a small computer," he picked up off the table a small circuitboard not much bigger than his thumbnail, "which divides up the image into overlapping pieces and sends each part to a tiny matrix of lights at the focus of its fresnel lens. The trick is to set the lights at the focus of the fresnel lens so that it displays a single color and brightness depending on the angle it is viewed from. So no individual lens displays an image, but all of them together do. And the image is different depending on the angle it is viewed from. The idea is to cover the drone, or horse, or suit with these and have just 6 wide-angle cameras pointing up, down, left, right, back front." He pointed at the little cloaking device. "That's the only one we've made so far. We'll have to make lots more."

"Wow!" I said. "It's like the invisibility effect the alien has in the 'Predator' movie."

Vincent nodded, "And it has similar failings. It doesn't match complicated backgrounds well, and it can be most easily seen if it moves against the background, or if the viewer is moving tangentially to it... uh, moving past it. Before the disaster they called it active camouflage, which seems a pretty good name. Many animals used something like it, especially marine animals, like octopus and squid. There had been some attempts by people to achieve it, but as far as I've been able to work out, nobody really succeeded... at least publicly."

(Read about active camouflage: https://en.wikipedia.org/wiki/Active_camouflage.)

Gabe said, "We won't be able to put them on the top of drones and horses, of course. That'd cover their solar collectors, but unless the military have flying machines or they look down on us from hills, that's not going to be a problem. And Kayla is looking into a way of camouflaging even those... thin strips along the collectors with the thin edge almost vertical, angled toward the sun, I think..." He looked at her.

She shook her head, "No success yet."

After a few moments, Maria said, "This sounds wonderful, and I would feel much safer out there with this gear, but I still have no desire to confront an armed soldier who has instructions to kill."

Gabe said, "Yes. On that point, Mum came up with an idea that should help." He threw a smile at Blossum. "She suggested decoys. We could use dummy images of people wearing hats and masks, like what we used to wear, way back when Jill and Kim rescued us. We can talk to the soldiers via loudspeakers behind the dummies. That way, if they shoot..."

"...they're not shooting at us." Charlie finished. "Nice."

Blossum said, "And I said we could cut off their radio aerials so they couldn't radio home, but Vikki said it'd look like we were, umm--"

Vikki put in, "We would appear to be attacking them."

She continued, "Yeah, so it'd screw up our chances of talking without getting shot at. She's right. Aimee came up with a better way."

We all turned to the entertainment screen. Aimee smiled happily. "It's pretty simple really. A drone drops a sock-shaped wire mesh over the aerial. It forms a Faraday cage, stopping radio waves from getting out. It's completely reversible by just lifting the mesh off. There is a slight catch. From what I've read, to work properly the mesh should be grounded — connected to the earth (maybe a wire dragging on the ground?) — though I can't see why a clip fastening it to any exposed metal on the vehicle shouldn't work, especially on the tracked vehicles. We should add an infrared transmitter/receiver to the top of the mesh and couple it to the aerial inside. That would let us communicate with the people in the military vehicles, but they couldn't communicate with their home base."

I said, "It would be tricky to talk to them in a non-threatening way if we're cutting off their communications. Perhaps we should begin by saying we'll restore their radio again in a moment, but that we've taken over it temporarily to make them an offer, which they are free to refuse or accept. There will be no penalty if they refuse. If they are sick of living under restrictive military rule, we can offer them true freedom — self determination, gardens in an oxygen atmosphere, birds, fish, flowers, fruit, and home-grown vegetables with a high technology lifestyle and a friendly, co-operative community. If they want this, it's theirs, without cost or obligation. At any time they are free to return to the military, though I doubt they'll want to, after experiencing freedom."

Jill smiled, "Not to mention that the military would probably imprison or even execute deserters... probably best not to dwell on that, though."

Matt very rarely spoke at our meetings, but he asked, "Say if a group of people in a vehicle do decide to leave the military and choose a Habitat, how do we help them separate off from the others?"

"We've had some discussion about that," Vikki said. "We still have no firm conclusions, but most of us think it would be best to get them to drive off some way to the side, then cover them with a camouflage blanket or hide behind some camouflage panels to make their vehicle seem to disappear. When it is safe to do so, we would transfer them to the luggage compartments of our horses and into pack mules, depending how many are in the vehicles, then remove the camouflage from their vehicle and hurry away to the nearest Habitat. We would leave their vehicle behind."

Dahlia said, "We'd have to insist nobody brings weapons."

There was general agreement at that.

Jill said, "We should get previous escapees to recruit new ones, because people still within the military system will naturally distrust us. They would trust their own more easily to tell of how much better life is away from strict military rule."

Charlie asked, "When should we tell them about our longevity — the antidote to aging?" When nobody had an answer to that after a few moments, he frowned, "I presume we are going to share it with others, right?"

There was a ripple of agreement among us. I found a number of people were looking expectantly at me. A little panicked, I said, "It's a choice for all of us; it isn't up to me... but if you do want my view, I think it would be immoral to keep it from others. At the same time we need to be careful with how we deal with them. If we're not careful, we could make ourselves targets for attack."

Jill said, "I think that ship has sailed already, honey."

"What I mean is, authoritarians have always wanted to keep things of great value for themselves and not share with anybody else, and throughout history and literature the idea of a fountain of youth has been one of the most sought-after and valued things. We don't want to put ourselves in greater danger." I sighed and shook my head, "I hate the idea of us having to make such decisions, but I figure, after people show they are not a risk, then we give them the choice... because it would also be immoral to just quietly infect everybody with it, simply to take the spotlight off us. Some people might not want it." I looked at Dahlia, Matt, and Hope sitting on her mother's lap. Dahlia nodded to me.

Cliff said, "After enough people have it then it's no longer remarkable."

Ben said, "Getting back to the topic of the other Habitats, it'll be years until they're built and working properly. What do we do about the military until then?"

Nobody spoke for a little while, then Blossum shrugged, "Avoid 'em?"

And that's what we did. We added active camouflage to the drones, horses, and suits and became adept at using them to best advantage, learning how to most effectively make ourselves invisible.

Aimee came up with a way to communicate long distance without using radio. She suggested using an infrared laser aimed at the underside of the clouds to bounce a signal to receivers about 150 kilometers away. The cloud base was about one kilometer up. At that height, the horizon is about 112 kilometers away. Put another way, a spotlight shone on the clouds directly above could be seen for about 112 kilometers. However that signal would be very faint at that distance. Aimee suggested the beam instead be angled so that it hit the clouds about halfway between the explorer and the habitat, but limiting it to no more than about 45 degrees from the vertical, which would put the illuminated spot about 75 kilometers away. The explorers' equipment should be able to see that for about another 75 kilometers. In practice, we shortened those distances to about 60 kilometers. When explorers reached that limit, now about 120 kilometers from the Habitat, they would establish a repeater station which would extend the range by another 120 kilometers. By slowly creating a grid we could communicate without much risk of interception. Lightning would still interfere with infrared, but if we had a grid we could route signals through areas that were free of lightning. There was a nice twist to this: the clouds, previously an impediment to communication, would become our medium. Another useful aspect was that infrared, being a much higher frequency than radio, let us encode vastly more information too. We could include much more redundancy and error-correction data in our messages, making them much clearer and free of crackle and hiss. Later, when the other habitats were occupied we used that network to send and receive great volumes of data at high speed, easily.

Communication between horses had existing modes (loudspeakers and microphones, infrared and visible optical) and added wifi — short-range radio that only reached about a hundred meters. We could increase the power to reach perhaps double that or decrease it, restricting it to just several meters. This let us communicate safely even in places with thick vegetation. The wifi could also be aimed by extending a tube around the short aerial. When aimed like that it could also extend the range by up to a couple of kilometers. I don't think we ever used that latter capability though.

Over the next several years, about fifty new Habitats were built and sterilised, and we established stable, self-maintaining, young ecosystems in them. For safety's sake, they were each a couple of hundred, to several hundred, kilometers distant from our Habitat, which became a bit inconvenient whenever we needed to do some hands-on work in them, but we didn't want new colonists that might return to militancy being close enough to easily find and attack us.

Early in that period, Kayla built a physical body for Aimee. She came to one of our evening meetings holding Aimee's hand to give her some physical support. Aimee was a little clumsy, obviously still getting used to her new physicality. Her hair and her silicone skin were black — much, much darker than mine.

Kayla explained, while throwing me a rare, brief smile, "Her skin color is purely practical. It is all solar collector so that she recharges just by being in light. Unfortunately, I've been unable to find any reference in the library, or to design anything myself that comes close to the capability of biological muscle, so there had to be a tradeoff between speed or strength. I chose to make her as fast as us, but that meant being much weaker."

Kayla was, at that time, a bit more than twenty, and had built for Aimee a sleek, slender body that almost exactly mirrored her own. I don't know if that was intentional or not. Jill later suggested to me that Kayla, always practical, probably just took measurements from the most convenient source available: her own body.

Aimee was delighted to be able to physically accompany us on explorations and maintaining the new Habitats. She had some great advantages over us, in that she didn't need oxygen or a controlled temperature, but she still wore a minimal protective suit so that she didn't have to go through decontamination. Without the extra equipment, her suit's lower weight let her move like us, since she was so much weaker. Her mind was physically too large to fit in the body, so it remained back in the Habitat. The body nevertheless contained a rudimentary AI, similar to the kind the horses had, giving it a small amount of autonomous control so that Aimee didn't need to send instructions for every little thing. Functions like walking, even over rough surfaces, were coordinated onboard the body. Aimee described it as like the difference between the human cerebrum and cerebellum. The cerebrum, the large, gray hemispheres of our brain, contained all the more complex memories and thinking, but routine functions, like walking, swimming and so on are handled by our cerebellum, behind and below the main bulk of our brain. Aimee's body contained the equivalent of a cerebellum. Her version of a cerebrum — her mind — remained in the Habitat.

Since contacting the folks in Montreal's Underground City, Kayla and Aimee had a burning desire to communicate more directly with them. A cryptographic key would let us communicate without being evesdropped upon. Meeting them personally would also allow us to give them volumes of information, including seeds of many of the Habitat's useful plants that had died out because they needed to be pollinated by insects, birds, and other animals. Also we could deliver frozen embryos of animals (mammals, birds, fish, lizards, insects, etc). With all this in mind Kayla and Aimee designed and built a kind of boat to take these things to the people in Montreal's Underground City. They didn't create it inside the Habitat. It was far too heavy. It had to be constructed in a river with access to the sea.

The vessel was made of the same material that slugbots laid down to make the hard inner surface of Habitats: calcium carbonate, with interleaved layers of protein. However the ocean was now very acidic because of all the carbon dioxide dissolved in it, so the vehicle needed an outer layer of polyethylene plastic to prevent it being dissolved. The plastic shell was made in sections in the Habitat's engineering labs and carried in pieces, by horse, to the construction site, where they were carefully glued together. Kayla let loose a couple of hundred modified slugbots inside it to slowly build up the main hull of the boat over several months. When it was done, the ceramic hull was more than a handspan thick and very heavy, so that, when all the water was pumped out, the ship rose to float under the waves, with just a small central part slightly above the surface. This meant waves left the craft mostly unperturbed. In rough weather it could compress air in some tanks, letting some water into them, to regulate its buoyancy, so it could sail deeper, under the turmoil of storms.

It was an impressively large vehicle, especially when you realised that, apart from the protective plastic shell, it was secreted by small, dumb slugbots.

The ship would be powered by sun, waves, and temperature, but mostly, it was intended to be a sailboat. However, instead of a conventional mast and sail, it would use a kite on a long cable to pull at an angle to the wind just as a sail would have, and the adjustable keel under the hull let it use that force to propel it in almost any direction. Why a kite instead of a conventional sail? Two reasons: the wind at great altitude was often stronger and could have a different direction to the wind at sea level, and when the ship needed to submerge, the kite could be reeled in and safely stored away from damage and without resisting the craft's movement. When there was either little wind, or the wind was too ferocious, the boat could ride the ocean currents. It had short wings that could propel it through the water if absolutely necessary. Kayla got the idea of the wings from watching videos of manta rays and penguins.

Most of us visited the craft several times during its construction, and afterward to help install fittings, and equipment. A watertight hatch door was hinged to the highest point of the top, and a ladder added. The mechanism to fire the kite into the air and wind it back in was bolted into the socket designed for that purpose. Rudimentary furniture and shelving had been built into the interior by the slugbots. We added doors to the shelves to keep things safe in heavy weather, and installed computers and other electronic equipment, along with backups and spares for everything we could think of that might get damaged. There was no easy way to safely add windows to the craft, so eight stereo pairs of tiny cameras were mounted around the perimeter, with another four pairs under the bottom of the ship and four more pairs at the highest point of the ship, around the entry hatch. Additionally, another stereo pair was mounted on the kite with a two meter separation — those last two had similar magnifying optics to the tethered drones we used when exploring.

When the slugbots had built the hull, they'd made a layer of quantum dot solar panels under the top plastic shell, before covering them underneath with the same ceramic as the rest of the hull. These solar panels would be one of its main power sources, but power would also be supplied by flotation devices harnessing energy from waves, and thermoelectric devices contributed a small amount of energy from the temperature difference between the top and bottom of the vehicle as conducted by heat pipes. The lower device could be dropped further below the craft to improve that difference a bit.

Rather than risk a human, Aimee had volunteered to clone herself to pilot the craft halfway around the world. As she explained it, she was the natural choice, because she didn't require air, water, or sleep. She had no fear, or pain, so if a calamity befell her, there was no anguish involved, other than feeling she'd let us down. She could take a library of information with her so that she could continue to learn along the way, and she would make measurements as she went — salinity, air and water temperature, wind strength, ocean acidity, and she would make periodic studies of the microbiology of the ocean.

Aimee and Kayla had studied the air and ocean currents as shown by archived pages of https://earth.nullschool.net, trying to find the simplest, quickest, most efficient way to Montreal. They ended up choosing a combination of air currents and marine currents. The journey was planned to take advantage of the ocean current travelling down the east coast of Australia to the so-called Trade Winds, which would carry the ship across the Southern Pacific, past the tip of South America, across the South Atlantic and up the west coast of Africa. At the Equator the westward moving ocean current would be used to cross the Atlantic, then ride up the east coast of the Americas. The last part — making it into the mouth of the St Lawrence river and south-west against its current to Montreal — would be the most difficult. And all that was supposing the currents of the pre-catastrophe world still ran similarly today.

The biggest problem was working out where she was at any time. The cloud cover meant measuring position by the stars was impossible. The original GPS satellites were still in orbit, but were about 50 years old and had originally been designed to last only about 12 years, however most of them lasted a good deal longer, so that if you waited for a while, eventually enough of the still-functioning satellites would come in range to give a rough location. And when travelling many thousands of kilometers, that was good enough. Also, the kite had a camera on it and let the person in the craft see more than a hundred kilometers in every direction, as long as the clouds were more than a kilometer above the surface. They usually were.

Cloning Aimee turned out to be a lot more difficult than had been expected.

As Aimee explained it at the evening meeting when they introduced Aida, the new AI, "The first, and greatest difficulty was that we are running low on computing equipment inside which to create another AI. Even though I don't need as many neural elements as a human, due to my much reduced sensory input and muscular output, I nevertheless still have enormous computational requirements. This is partly because I have the equivalent of about 10 billion neurons. (A neuron is a nerve cell — a human has about 86 billion of them.) And each of those neurons has potentially something like a thousand synapses connecting to other neurons. Each of those neurons and synapses had to be simulated by programs storing data in very large RAM arrays. Kayla and I solved the equipment shortage problem by designing new computing elements using some of the microfabrication techniques she had developed to make quantum dot devices and the programmable elements in her antbots and slugbots."

Kayla added, "And your insights into self-assembly we used for the solar trees."

Aimee smiled, "In approaching the problem fresh we realised that some of the obstacles that plagued conventional microelectronics, like quantum tunneling — where electrons can randomly jump to nearby conductors if they're too close — could instead be used to design new logic elements for an AI. The new devices were self-assembled entirely out of carbon grown from carbon dioxide in the air. Three dimensional structures of atom-thick graphene sheets were grown into circuits that employed shape, topology, fields, and quantum effects, and they were insulated by regions of diamond similarly grown. Graphene is a much better electricity conductor than copper, so it generates far less waste heat, and diamond is an excellent electrical insulator while being a superb conductor of heat. The diamond regions also let the AI use light for some of its computational functions. This design allowed us to greatly reduce the size and energy requirements of the new AI without needing to scavenge for more electronics."

Maria raised her hand slightly, "Can this technology be used to replace some or all of the Habitat's existing electronics?"

Kayla said, "Yes, probably... some of it."

Vincent asked, "What was the second problem?"

Aimee looked puzzled, "Hmmm?"

Vincent said, "You said there were two problems. The first was the lack of computer equipment. What was the second?"

Aimee nodded, "Oh, yes. Kayla and I had greatly under-estimated how long it would take. It was reasonably straightforward to get all the readings necessary to describe my brain, but then transferring that data into the other purpose-built AI was much harder. It wasn't simply a matter of reading the values in the RAM and copying them into another bank of RAM running the same program. My program uses self-modifying code in order to achieve the kind of flexibility that a biological brain does. Your brain, and mine, doesn't just passively store data about its connections, it actively builds new connections and loses some old connections to other nerve cells. Also, because the new AI uses a number of completely different, much more efficient techniques, it was not simple to translate the conventional program plus data into something where much of the program and data are the structure itself. It was a very long and complicated job. And then, after all that, we had to run a very long set of tests to make sure we got it right. But all that's done now."

Aida had a body just like Aimee's, though they gave her red hair to make it easier for everybody to differentiate between them. The combination of red hair and black body made her very striking.

Aida, strictly speaking, did not really need a body for the journey, but duplicating the minds without a matching body made it more difficult to test whether her mind worked properly. Aimee pointed out that she could have used her body, but Kayla thought the journey would be safer and easier for Aida if she had a body, and would also make contact with the people in Montreal easier too. In practice, Aida would be able to easily swap her point of view between using the craft itself as her body, and using her humanoid body. She could also switch to a virtual world inside the ship's computer. But she would always be just a call away, because she could chat with us via radio, except when she was underwater. Physically, Aida's mind remained inside the ship and connected via radio with her body.

Aida, of course, had the same bright, uplifting personality as Aimee, so it was with some sadness that we all gathered at the river to say goodbye. She hugged each of us, then turned and scrambled down the embankment to the water's edge. She jumped onto the black, upper surface of the craft, sending small ripples out onto the water, then went to the hatch, lifted it, and started climbing down. She paused with just her head and shoulders out and waved to us. In our earphones she said, "Goodbye lovely people." We all waved back, with a smattering of goodbyes from us. Then she pulled the hatch down, and locked it. The clasps unlatched from nearby trees and their cables reeled back into the side of the ship with a whir, splash, and clunk. A moment later, we could see, under the water, the wings on each side began to undulate slowly, and the ship gently moved out, away from the river bank. She let it drift with the river current, taking it out to the sea. She wouldn't use the kite yet because the onshore wind would work against her.

We all watched until the top of the ship was barely visible, then went back to our horses, and home.

* * *

part 16 - Aida travels

We kept in contact with Aida, chatting by encrypted shortwave radio, and unencrypted to the folks in Montreal, and to various other groups around the world that were part of that communication network.

About a week into Aida's journey, we were all in the main livingroom having our usual nightly meeting, but including Aida through the radio, and Aimee had just told Aida that she'd realised the New Zealand group was in the National Aquarium in Napier.

Jill asked Aimee, "What makes you think they're at the National Aquarium?"

Aimee answered, "A couple of the names mentioned during conversations with them — I remember seeing those names in some science news I was reading in the InternetArchive dated a few years before the catastrophe. The New Zealand government had given the Aquarium a lot of money to hire a bunch of researchers to do important work there, and to expand its buildings out into the bay, under the beach and under the water. The politicians insisted on it being under the beach to avoid affecting the appearance of the area — "responsible tourism" had become important — and under the water because the land under the bay cost nothing, despite being almost in the middle of the city, while aligning perfectly with the marine science/education/tourism intent. The names mentioned over the radio were some of the newly hired, promising young scientists that the news article boasted adding to their staff. They would be in their seventies or eighties now. I also recalled some research papers they'd written warning about the rogue algae. I put two and two together. It just makes good sense."

Jill looked worried. "Let's hope no bad people listening to the radio have your penchant for reading old science articles."

Aida wanted to visit them. We all agreed that was a great idea. She also thought it made sense to try to visit as many of the other colonies as possible, all around the world. We regretted that we had not included a horse on the ship for Aida. That would have made it possible to visit some of the inland groups in many countries too, most notably USA.

With that in mind Kayla and Aimee began designing and building a bigger ship that would contain much more equipment and gifts. They intended it to hold two horses and several drones, as well as spare parts for everything, which would make it possible to visit many more places around the world that Aida could not. Unfortunately it would take about a year for Kayla's army of slugbots to build the much bigger craft as it also needed a significantly thicker hull.

While the new, larger ship was being made, Kayla and Aimee began work on a second AI clone to pilot it. Having done it before, this AI was a lot easier and quicker to make, though the testing phase was just as time-consuming as before. This time, improvements let the brain be physically smaller, enabling it to be put inside the AI's body — specifically in the belly. This was necessary if the AI was to venture any great distance from her ship.

Kayla and Aimee introduced her, as usual, at the evening meeting. She was named Ailis, and had blue hair, but otherwise looked exactly like Aimee and Aida.

Because the new ship took around a year for the slugbots to create, Ailis spent a lot of time working with us in the Habitat. She also helped Kayla and Aimee make more suits, horses and drones, some of which would be accompanying her on her sea voyage the following year. She enjoyed coming with us on expeditions to the new habitats to help fit the new spaces out with plants, insects, birds, and other animals. Her ability to move freely, unrestricted by Aimee's need for a link back to the Habitat inspired yet another cloning of Aimee's mind into a compact brain. This one was put into Aimee's body. The original version of Aimee in the Habitat's computers was archived in case it was ever needed again. This freed up much of our computing power for other, more traditional uses.

During this time we continued to explore further north, west, and south. Since our brief and scary encounter with the military we used active camouflage, and were particularly careful when searching south. We didn't want to meet them again before we had other habitats ready to offer to any who might want to escape from a life of regimentation. We did, however, meet a small family when we were travelling through the hills west of Newcastle.

We had spent the morning extending our communications by installing an infrared laser repeater on the highest mountain in the area, inexplicably named on maps as "The Sugarloaf". We were heading east, toward Newcastle, to see what we might find of use there. Aimee was with us and was operating the tethered drone, as she enjoyed doing. The distorted view made most of us humans nauseous after viewing it for any length of time. She was examining the surrounding country with its telescopic vision.

"Hey! I saw movement!"

We all stopped immediately.

"I don't think it's military... it's in a little, protected valley." She put the central, magnified partion of the image on our horses' screens. "A couple of kilometers over that way." She pointed off to our right.

"There it is again!"

None of us saw anything on our screens.

She said, "I'll fly one of the drones over there to check it out."

While she was doing that, we surveyed the easiest route there, then started forward. Aimee was concentrating on the view from the drone, using her wonderful AI abilities to look through it's eyes, and had set her horse to simply follow ours automatically.

Several minutes later she shouted triumphantly, "I see it! A person working on a garden." She put the view on our screens and we all stopped our horses to safely watch. There was a person in hat, cloak, and gloves kneeling in an open-air garden. Nearby, there were a couple of glasshouses covered in shadecloth. We couldn't see if there was anyone inside them. As we watched, the person stood, brushed off the dirt from their gloves, picked up a basket, turned, and walked toward the nearby house. The house was at the edge of a football field-sized cleared, grassy area, in the middle of which were the garden and glasshouses. This was nestled in the bottom of a protected valley. Beyond the cleared area was bush in all directions, for kilometers.

"Wow!" Ben whispered hoarsely.

Maria said, "Okay, how should we handle this? We don't know if they're dangerous or if they would welcome strangers."

I suggested, "Maybe we should approach behind the cover of trees rather than crossing the clearing."

Aimee said, "Would that inspire fear? Be seen as creeping up on them? Perhaps we should stop on the road beyond the clearing and I should get out of my horse and approach them with my camoflage switched off. If they're provoked to attack, getting damaged is less of a problem for me."

We grudgingly agreed.

It took us just under an hour to make our way there. We stopped just out of sight, beyond a bend in the unpaved, overgrown path to the place. Aime slid forward the side panel on her horse, pushed the suit out and got into it through its belly, then detached it from the horse.

"I'll leave the panel open in case we need to leave in a hurry." She switched her camoflage off, so her suit went shiny black. "Hmmm... I'll switch the camoflage back on, but set its computer to show all white. Walking in with a shiny black suit might look a bit sinister."

She set off on foot along the track. We watched, swapping between peeking through the trees, or observing from the point of view of the tethered drone (reeled in to just above the trees so as to hide the tether), or another drone circling over the clearing, or Aimee's point of view. All of us, except Aimee, remained invisible.

Aimee walked toward the house, waved and called out in as cheery a voice as possible, a bit muffled (we didn't have loudspeakers on our suits), "Hello? Can I have a chat? I was just in the neighborhood and was surprised to see you. You were in the garden. I wonder, can I talk with you? I intend no harm. I have no weapons. Hello? I didn't expect to see anybody out here. Most of the survivors we've found have been in towns. Hello?"

She continued this way, unhurriedly until she reached the verandah of the house, then she walked up the steps, still calling out, and knocked on the door. "Hello? Can we talk? I come bearing gifts."

The door opened and a worn-looking, slim, gray-haired man wearing a respirator stepped out, closing the door quickly behind him. He might have been in his sixties. He held a large knife in his hand by his side and he was obviously very nervous.

We could hear over our horse wifi Aimee speaking gently, "It's alright. I bring things to help you. I don't want to take anything. You're perfectly safe. May I come in and chat?"

Aimee was so lucky Kayla had designed her to be without fear. I'd be positively vibrating with nerves at that point, but she was cool as a cucumber.

The man looked at her for a few moments, weighing up possibilities, then reopened the door, stepped in without turning his back to her and beckoned her inside impatiently. Aimee followed and the strength of her wifi signal dropped appreciably. We all increased our sending signal. I was about to ask Aimee to boost hers too, but by then she already had.

The man took off his mask and turned the air feed off. He said, "You can take your suit off in here. We have oxygen... obviously."

"Thank you, but I can't. Our place is free of the algae that caused the catastrophe. If I take the suit off I'll be contaminated and will contaminate the inside of my suit and my vehicle when I return to it. I mean I could, but decontaminating all that later would be such a hassle, right?"

"Okay, so what do you want?"

"I want to offer you a few things. You don't have to take any of them. The choice is all yours. And you can change your mind any time."

The man's eyes narrowed. "Sounds like you're selling something." He was holding the knife threateningly.

"I can walk out of here if you really want and never come back, but since you stand to gain greatly from this, please at least hear me out."

He still looked very suspicious. "What's the catch?"

A door to an adjoining room opened and a gray-haired slender woman entered and walked over to Aimee and the man. "Geez, George! You're too suspicious. First human contact in half a century and you're about as welcoming as an angry snake. At least offer the girl a seat. I'm Marjorie, dear." She pulled out a chair from the table in the middle of the room, sat, and waved Aimee to sit too.

George sat, placing the knife on the table, and said, "Okay. Say your piece then."

Aimee said, "Actually, it is good to be suspicious. There are some bad people out there that it's best to avoid, if you can. If you ever see any large, military vehicles, do not make contact. They are dangerous."

George raised his eyebrows and looked at Marjorie with a told-you-so expression. Marjorie rolled her eyes and smiled.

Aimee continued, "With that in mind, we can offer you a few things. We live in a place that has conditions like those before the catastrophe. We can wander around our gardens without masks or protective gear. We have a cooperative community of 17 people. We farm and have a lot of high-tech gear. One of our members is currently on a sea voyage around the world to contact other communities. We've been building other places for people we meet so that they can stay safe from the military. We can offer you one of our existing places — it's unfortunately almost a week's travel away. Or we can build a place here for you. It would be underground so would not impact your farm, other than creating a large mound of earth. The biggest disadvantage is that it would take some months for it to be ready for you to move in, and then time to grow plants and add animals."

Their mouths fell open. "Animals?" Marjorie asked, "You have animals?"

Aimee smiled and nodded. "In the meantime we can establish communications with you, letting you call on help if you need it. We also have a massive library of books, videos, and a copy of much of the internet from before the catastrophe. All this would be shared with you... even if you don't want to join with us."

George frowned. "What's the catch. What do you get out of this?"

Aime said, "There is no catch. What we get out of it is more people. The catastrophe made human life incredibly scarce. The more we help each other, the more resilient we all become. We want you to be safe. That helps us be more safe too." She paused. "You're really asking what the down-side is, yeah? Well, the danger is mostly to us. We have been put at risk by people we've encountered before. We won't let you anywhere near our main home until we can be completely satistfied that it's safe for us to do so. But until then it doesn't hurt us to help you, and it's actually to our advantage to do so. The better off each person is, the better off we all are. Each person has capabilities that other people don't. Untapped, they're lost to everybody. Encouraged and enhanced, they can benefit us all."

George said, "Well, this place you said you could build here. We don't have the resources to feed and look after a bunch of builders, so you can forget that."

Aimee shook her head, "There would be no people. The process is completely automated. The first part would be to let some solar trees grow. They look very much like normal trees, but they support hundreds of small, leaf-sized solar panels. They supply the electronics to feed ant-sized machines that will excavate an underground place. The ceiling of the place will produce light very similar to the original, pre-catastrophe sunlight. Plants grow well in it, and it's very much like walking around in the open, except there is no need for masks or protective clothing, because like in here, it will have oxygen rich air. We would bring bees and other insects, and birds, and fish... possibly even some goats in the future, when you have even more room. All these would live in the place with you. The idea is to build a self-maintaining ecosystem to make you safe and independent."

Marjorie said to George, "Bees would mean we wouldn't have to hand-pollinate plants anymore. That'd be nice."

George asked, "How long would all this take?"

"A few months. The solar trees grow from seeds," she made an indication of the tennis-ball-size of the seeds with her hands, "reaching useful size in a few weeks, but they don't have to be used only for the underground place. More can be planted to give this house extra power. I notice you already have solar panels on the roof. I'm very surprised they survived the hailstorms. How did you manage that?"

Marjorie said, "When the roads were okay, we went to the nearest town in our electric car plus trailer and got the plate glass from store fronts. That stuff is really strong. We put it over the panels to protect them. Same with the glasshouses. They're all that same kind of glass."

Aimee nodded, "Good solution... one we never thought of. See? That's what I mean about every person being valuable. But returning to the topic of timing — the underground place takes months to excavate. We would have to return at that point to add the plants and animals and electronics and furnishings, as well as the isolation system so you can keep it safe from the algae. You mentioned your electric car, and that the roads everywhere are pretty-much impassable now. We'd give you an alternative mode of transport. We call them horses." As we saw in our video feeds, Aimee turned to the window. "Kim, can you walk your horse up to the house to show them please?"

I turned my horse's camoflage off and did as Aimee said. I waved to the two people looking out the window.

Marjorie called out, "Boys, come here and look at this!"

Aimee turned to see two young men in their thirties come out of the room Marjorie had been in. Seeing them on the horse's screen, from Aimee's point of view, walking swiftly toward her, made me suddenly fearful. But they walked past her and peered out the window at my horse. I waved again for their benefit, even though I knew I was little more than a silhouette inside the louvred cockpit.

Aimee said, "We'll bring back four of them for you and show you how to use and repair them. They'll make you mobile again. We'll also bring you some suits that will make it easier, more comfortable, and safer to move around outside here too. When the underground place is done you can move in if you wish, or simply use it as a farm. It will be entirely your choice. I think you'll like it though. It'll include a communications system that will give you access to all the information we have, as I said, but it will also let you contact other people all around the world. We have other gifts, but they will depend upon whether we think it is safe to give them to you."

One of the young men grinned, "You think we'd hurt ourselves?"

Aime shook her head, "No, we're worried about the risk to ourselves." Aimee was probably thinking of the anti-aging treatment.

Aimee turned away from the window and walked back to the table. She sat. "So, what do you think? Do you want any of this? You don't have to answer now. We'll leave a comms system that will let you contact us anytime. We'll be in the area for a while. We're on our way to Newcastle to see if there's anything useful to us there."

George said, "We'll think about it."

But Marjorie shook her head, "Screw that! Yes, we'll accept it. And thank you."

Aimee rose, "No worries. Kim's horse has a spare communicator, and some seeds for me to plant some solar trees. Where do you think would be the best spot for the underground place? I'd suggest for it to be fairly close to your house to make the move easier if you decide to move in. Perhaps in that bare area behind and to the north side of the house?"

Marjorie and George looked questioningly at each other then nodded. Marjorie said, "Yeah, we used to have a shed there, but it blew down one year, so we scavenged its parts for repairs to the house."

"Okay, before I go and get started, is there anything else you want to know?"

They all looked at each other for a couple of moments, then one of the young men asked, "When can we get some videos, and books and stuff?"

"Today. As soon as we connect up the communications system. That will let you access everything we have." Aimee pointed at the large, flat-screen TV. "Does that work?"

One of the young men nodded, "Yeah. We sometimes watch videos on flash drives, but not much anymore. You get sick of watching the same ones too many times."

"Okay, we'll connect it to that. I'll go and organise the solar trees, and get Kim to bring the electronics in. She'll connect it up."

She went outside to my horse, which was now settled on its belly. She opened the back and got a bag of fist-sized solar tree seeds while I was still wriggling out of my horse into my suit. I brought in a communications system from the back of my horse (we always carried some as spares), and after greeting everybody, I set it up with the TV. Then I went outside the house and aimed the infrared receiver-transmitter so that it would get the best reception from the clouds above the repeater on Sugar Loaf mountain. Lastly, Aimee and I went back inside the house and spent about an hour showing the family how to access things and how to contact us if they needed help, or just wanted to talk. We also took their quick measurements so we could make suits for them.

We were about to leave and Marjorie asked us what they could do for us as thanks. I started to say no thanks were needed, but Aimee interrupted me, "Actually, you might be able to do something for us. What kind of food do you grow? If you have something we don't, perhaps we can take some samples back with us."

It turned out that they did have a few plants of interest, so with thanks and waves, Aimee and I left to rejoin the rest of our team still out of sight down the path, behind the trees. Then we continued to Newcastle, chatting from time to time with our new friends and everybody back at the Habitat.

We carefully explored Newcastle, though didn't find much of use there, like much of the Sunshine Coast in recent years, it had become largely flooded. The horses let us wade through swamps and even swim over deeper water, but a lot of what we found was ruined. When we did find anything that was useful, we checked with Marjorie's family first, showing them our video feed, to see if they wanted it — depleting the area of what they might scavenge didn't seem right. We would only take it if they didn't want it. Anything that they wanted, we carried back to them and dropped it off to them when we returned. This time we walked all the horses up to the house, as they'd come to know everybody through our online conversations anyway. We kept the camoflage turned off, because we didn't want to mention it to them yet. If the military came here, we didn't want anybody accidentally neutralising our only protection.

At that point we'd been travelling for nearly two weeks and were starting to sorely miss home, so decided to finally head back north. We'd originally intended to explore as far south as Sydney, but we figured we'd already accomplished a fair amount, and it is really tiring to live for weeks at a time mostly cooped up in the horses. Aimee was the only one who would have been perfectly happy to continue. We decided to go back by what looked on the maps like a more direct inland route: Tamworth, Armidale, Tenterfield, Warwick, Esk, and home. Though as we later realised, that was along the Great Dividing Range and not as direct as it initially appeared. Much easier would have been to go much further west via Moree, where the land was much flatter and the roads were still mostly intact. It took us another two and a half weeks to get home. There was some compensation in Armidale having a large university where we were able to find lots of useful equipment.

During our return journey, regretting the difficulty of travelling on the mountainous terrain, especially in places where the road had been broken, we had a lot of time to talk about the alternative route, further west. Looking at the maps, Aimee noticed Lightning Ridge was about two hundred kilometers west of Moree and became excited. She explained that there would likely be some survivors there, as she'd read that some of the town was underground. So we resolved that we would visit it in one of our next journeys. Otherwise, the journey home was boring and annoying. There were plenty of obstacles and challenges along the way, but it we were tired and just wanted to get back to the Habitat. If we'd been fresh it probably would have been much more interesting.

A couple of weeks after our return, Kayla sent the albatross drone out to drop a container of antbots and slugbots at Marjorie's family's place, under their still growing solar trees. We alerted them to it beforehand to avoid surprising anybody and switched its active camoflage off, to show all white, as it approached their place so they could see it.

A few months after that, their first habitat was ready to have everything installed and be sterilised, so we travelled down there again (using the easier inland route this time). We brought four extra horses full of gear following us automatically as pack mules. They were also to be left as gifts so Marjorie's family would once again be mobile.

We'd been long-distance chatting to them during our journey there, and they eagerly received us when we arrived.

They happily showed us behind the house. A large mound, almost the height of their house was now where there had previously been a wide, flat area. The rise was already nearly covered with grasses and some weeds. We walked around to the back of that, to a smaller mound adjoining the larger one, and began digging away the side of it until we encountered a hard, ceramic surface. We drilled into that, and assembled and bolted to it, a door large enough to easily walk a horse through, then broke through the relatively thin shell of the entryway and walked down the self-lit, gently inclined ramp, which curved around the side of the main structure, to the bottom, where we installed the second door, which together with the first, formed an airlock. This was the entrance to the garage. It was an area large enough to hold about ten horses. In there we set up an oxygen extraction machine to make the air in the garage and habitat breathable so that it would be much easier to work in there. (The extracted carbon dioxide was piped back up outside.) We brought all the horses in and parked them there.

At that point we took a break for some hours to let the oxygen build up in there.

When we went back to work, we added the suit portals to the gaps in the garage wall. In the decontamination room we installed the UV lights, fans, and hot showers, and a door to the garage on one side and to the habitat's living quarters on the other. That would allow them to bring new, contaminated items in from outside without putting their habitat at risk.

Unlike our Habitat, the garage and decontamination room were all on the same level as their living quarters, under their habitat's "ground level". This gave maximum room over to the gardens. While we were putting the finishing touches to that, the family members walked around inside it, amazed by the habitat's brightly lit "surface" — its pretend sky. It tearfully brought back memories for the parents of what the world used to be like, long ago. For the two younger brothers it was a novelty. One of them said it was like stepping into a world they'd only known from videos.

At last it came time to sterilise the habitat, so we all left it for a day. We slept in our horses; the family retired to their house.

The next day we explained to them how to use the decontamination room, then how to get into their environment suits in the wall between the habitat and the garage, detach safely, then attach to a horse, and wriggle out of it into the horse's cockpit. We showed them how to operate the horses, including the active camoflage (that really wowed them) and how to use it to best effect, remaining as close to invisible as possible.

For me, it was a very strange experience to see all this newly, from their perspective, as weird and wonderful, almost alien technology. This was all entirely new to them. They hadn't seen our countless incremental steps and small improvements over many years that had brought us to this point. The horses, for example, had gone through myriad revisions and upgrades until they reached that design. (Even now they continue to be improved.)

The last thing to do was to install equipment and furnishings in the living quarters and engineering rooms inside the new habitat. Those were all under the habitat's "ground level". It took a day to move the things in, through careful decontamination, and another day to dry the blankets and clothes from the washing, but eventually everything was done. The kitchen, bedrooms, bathrooms, storage rooms, and engineering room were all set up and working — water pumps, ventilation system, communications, cold storage, and all the rest, all checked out and working. Marjorie's family wandered around almost as if in a dream.

We all assembled in the habitat's main living room.

Maria stood before everybody. She said, "If you have any questions you know how to contact us. There is documentation in the computer on all the systems, and you already know how to access the computer. Eventually we would like to add a backup computer system here in case anything happens to the communications. Just in case." She paused and threw a querying look at the rest of us. "Age? Is it time?" We all nodded, so she continued, "Folks, we have another secret to give you, if you want it, but you must first promise that you will not tell others about it without consulting us first."

Marjorie smiled, "This sounds very mysterious."

George said, "How can we promise before we know what it is?"

Ben said, "You'll understand why.."

Marjorie elbowed George and said, "Of course we promise. Right lads?"

Her two sons agreed, and, reluctantly, George did too.

Maria said, "We can slow aging, so as to let you live for maybe another hundred years or more. In the case of you two, Marjorie and George, it will initially make you feel quite a bit younger first." She indicated Vincent, who now looked as if he was in his forties, "My Dad is in his nineties."

Vincent gave a little wave and smiled.

I said, "Not everybody wants this. Two of our members, back home, have chosen not to extend their lives. It's up to you. If you want it, you're welcome to it. If not, that's fine too. But we need to keep it secret because if the wrong people find out about this they could cause problems, wanting to have exclusive control of it, denying it to everybody else."

George gave a skeptical look, "But isn't that what you're doing?"

I was surprised, "No, not at all. We want to give it to everyone, including those who would like to restrict it. We're being careful because we want to make sure nobody gets a chance to prevent others from choosing a long life if they want it."

Ben said, "Imagine if some bullies get ahold of this. They would keep it for themselves to tighten their rule. They'd let some trusted lieutenants get it, but they would probably not be keen on the slave classes getting it. This would give them control. That's not what we want."

In the end, they all wanted it, so we dosed them and waited for a while to make sure there was no unexpected allergic reaction. Then, after hugs and waving goodbye we departed on our return journey.

We were going back the same way we travelled here, but turning west at Narrabri, intending to go through Walgett to Lightning Ridge to see if there had been any survivors there. However we never got that far. Long before Walgett, our drones spotted military vehicles kilometers ahead of us. We found out later that they'd had the same idea and not found anybody. We slipped off the road into the forest that now blanketed the outback.

We had often rehearsed a plan to separate a vehicle off from the others in order to offer its occupants a chance to escape the military. Now we put it into action. We hid by the roadside shielded by bushes and hidden by our active camoflage. When they passed, we sent a drone out to drop a wire sock over the antenna of the trailing vehicle, cutting off radio communications. Then, through the infrared tranceiver on top of the sock, we sent a message to that vehicle, "Stop. We have temporarily taken over your communications. We will return it to normal in just a few moments. We wish to make you an offer. Hear us out. It will only take a minute."

That vehicle stopped and we anxiously watched the rest of the convoy continue on their way. They hadn't yet noticed their trailing vehicle had been left behind.

We sent the offer. "We give you the chance of a life free from the military. No bosses. You will live your life on a high tech farm of your own, in an oxygen atmosphere, under a blue sky, with plants and animals, friends and family. You are free to accept or decline. If you don't want to be free then you are welcome to go. We will restore your radio and you can rejoin your fellows. If do you wish to be free, then exit the vehicle and we will take you to your new home. No harm will befall you. We are a society of people who want to live in peace, and the military are a threat to that. But we want to use peace and a good life to undercut that threat. What is your choice? You have a few minutes to decide. After that, your radio will be restored, you will rejoin your convoy, and your chance to escape will be gone."

The hatch in the top of the vehicle flung open and two masked people climbed out, jumped to the ground, and ran toward a couple of decoy figures we'd placed in the bushes. Another person popped up out of the hatch waving a gun and shouting, muffled somewhat by his mask, calling them deserters, ordering them to return. Two of us, hiding in the bushes told them to get down and we put up an active camoflage screen. At the same time a drone dropped a thin, black, plastic sheet over the figure as he was aiming his gun in the direction the two escapees had headed.

We hurried the two fugitives into the luggage compartment of Ben's horse. "Excuse the uncomfortable cramped space. It's temporary, until we can get you safely away from the gunman."

By the time the angry man on the military vehicle had thrown off the black plastic sheet, the drone had removed the sock from the aerial, and we'd retreated further into the forest, just for safety's sake.

From a vantage point barely above the trees, the tethered drone watched invisibly as the angry person jumped down from the vehicle, ran to where the two had vanished, then ran back to his vehicle to radio the rest of the vehicles. We listened on our radios as he explained what had happened and requested assistance in finding the deserters. His request was denied and he was ordered to rejoin the convoy. The vehicle then moved away to catch up with the others, now about a kilometer away. Thankfully, we wouldn't see the military vehicles again on that trip.

We stopped and turned off our active camoflage. Ben and I got out of our horses into our suits. Ben knocked on the lid of his horse and asked if it was okay to open it. "Do you have your masks and goggles on?" Only opening it when they answered that they did. We shook hands with the two there and introduced ourselves. His name was Ian, hers was Sylvia.

I said, "It would be more comfortable for one to ride in here and the other to ride in another, but we understand if you prefer to remain together — it's your choice and you can change it any time you want. We have about a sixteen hour ride to the nearest habitat."

"Habitat?" Ian asked, his voice muffled by his mask.

"I'll explain in a minute when I'm out of this suit and we're on our way again."

They preferred to stay together in the back of Ben's horse, so we continued on our way.

Back inside my horse, I said to them through Ben's comms, "The habitat is a place that can be yours — a gift to you for as long as you want it. As we said, you'll be under blue skies with plants and animals, like before the catastrophe. You'll have fresh fruit and vegetables, and a vast library of information, hundreds of thousands of books, and movies at your disposal, and you will be part of a growing network of peaceful friends, if you wish to be. You're also welcome to ignore everybody else and become hermits. You're under no obligation. You're free now."

Inside the back of Ben's horse, oxygen restored, they were able to pull down their masks and goggles and we all talked with them as we cut across, eastward, through several kilometers of forest, to rejoin the Newell Highway, north of Narrabri. This was to avoid any risk of encountering the military convoy again. From there we travelled north almost to Goondiwindi, and to the closest available habitat. Everybody was very interested to meet Sylvia and Ian virtually. We chatted over the network with them and each other for hours. We told them how the habitats worked and they told us about their life in the military.

Sylvia did most of the explaining, "As perhaps you've probably guessed, we're romantic partners — have been for a couple of decades. We'd been trying for years to figure out some way to escape. Life in the military is degrading. We worked hard, for no benefit to ourselves, and as little more than slaves. All benefit goes to the politicians and military top brass, who live in high luxury. The commander of our vehicle was a particularly cruel mongrel who had put in a request to have us split up. As far as we could work out, his only reason was that he hated to see us happy."

Ian said, "I think he was jealous. He was alone and it annoyed the crap outa him to see subordinates having what he didn't."

Sylvia continued, "We were dreading assignment to separate groups, so when your offer came over the radio, it was an irresistible opportunity."

Ian said, "I knocked the commander down, giving Sylvia time to escape, and I followed, expecting to be shot in the back. And then you folks came out of nowhere... literally. We had been surrounded by bush then suddenly you were right there beside us urging us to get down. I looked right at you and could hardly see you. Like you're almost invisible."

Ben said, "Yes. We don't have any weapons, but thanks to some of our talented team we have near invisibility and some other tricks to keep us safe."

Maria added, "And from now on they'll keep you safe too."

Sylvia said, "You know, It's not that everybody in the military is bad. Most are good people. It's just that the people at the top are dishonest, power-hungry people who seem to lack empathy. Having people like that in charge of a command structure poisons it all the way down. I think most people are just trapped."

Ian said quietly, "It's more than that though, honey. It changes people and encourages them to become vindictive. I've had friends from decades ago, who were good people back then, but have become angry and now enjoy hurting others. If it was just a few bad people at the top I don't think it would have persisted so long. Good people would have changed it."

I said, "We've been in contact with survivors all around the world. It would appear you may both be right. The Military in USA either had good politicians at the top, or removed the politicians. In any case they've apparently become a force for doing good, helping other survivors they encounter."

Sylvia and Ian told us a lot about the Australian military, their tactics, their weaknesses, the danger they represented. We, of course, told them about what we were doing and what we hoped to achieve.

When darkness fell, we decided to continue on. We don't normally like to travel at night, but we didn't want to keep Sylvia and Ian cooped up any longer than necessary.

Eventually we arrived at their habitat after midnight. The door opened at our approach and we steered our horses down into the habitat's garage. The top door and the lower one both closed behind us and the lights came on ahead of us. We parked the horses and told Sylvia and Ian that they could come out — this was a breathable atmosphere.

Maria explained, "You need to go through decontamination so that you don't introduce rogue algae into your habitat. Our suits keep us free of the algae." We squirmed into our suits. I showed them to the decontamination room and explained the procedure to them, then went back into the garage, and like the others, attached my suit to the wall and limbo'ed out of it into the habitat. It was nice to walk around freely again.

We all met them at the exit from decontamination where they wore white dressing gowns and were towelling their hair dry.

We gave a brief tour of the living quarters, how to use the comms, the refrigerated food store, the bedrooms, engineering and storage rooms, and so on.

I asked them, "Do you mind if we stay here overnight? Reduced visibility makes it unsafe to travel in the dark. Also, in the morning the larger space of the habitat will be in daylight and we'll be able to show you the gardens and explain the rest."

Sylvia laughed, "This is your place. Why are you asking us?"

I smiled back, "No, this is yours, now."

Ian laughed too, "Of course you should stay."

Maria yawned, "I don't know about you folks, but I'm totally beat. I think I'll go to bed right now if that's okay with everybody."

Ben agreed and followed Maria. We all thought sleep was a good idea, though I suspect Sylvia and Ian were too excited to sleep right away.

In the morning, I was chatting quietly with Vincent when Sylvia and Ian woke and came into the room, grinning, excited. I asked if they wanted some breakfast, but Ian laughed and said, "Nope, we want to see the rest of this place."

I beckoned them to follow us upstairs to the habitat's surface, which was now lit for daylight. They emerged through the glass doors into the simulated sunshine and the buzzing of bees in the flowers of herbs and shrubs, fragrance sweetening the air. Butterflies flitted and drifted lazily between plants. Small birds twittered. Out of sight, under the foliage, hens gossiped among themselves.

The trees were still only very young, with few taller than a person. This gave an unobstructed view of the size of the habitat, which was a hundred meters across — occupying an area about the size of two football fields side by side.

Vincent said, "Many of these, what look like shrubs, will grow into tall trees in years to come. There are fruit trees, nut trees, and some that provide other useful products. Some are fast growing, others are slower."

I pointed nearby to the right, "We'd already installed a variety of vegetable gardens. All the instructions you need are in the computer. Most of the plants and animals here should keep a balance without you needing to do much. It will go out of balance from time to time, but the solutions are generally pretty simple. Add a little more of one thing or take away a little of another, and it falls pretty quickly back into balance. You can always contact us for help. Share some of the produce with the birds and insects and they'll keep the place healthy."

Vincent pointed back into the door, "The fridge, freezer, and cold-room are already stocked up so you have plenty of food for the best part of a year even if the habitat failed to produce anything... but it is already producing." He pointed over to the clucking of chickens, "The chooks are laying, between them, roughly four eggs each day. (You'll probably have to find all the old ones and discard them as they've probably gone off — you don't have a rooster yet, so the eggs aren't fertile — they won't hatch.) Many of the leafy vegetables are ready to be eaten, some berries will soon be ripe. I'm not sure about the root vegetables, but I expect some of those are ready too. You can't see it from here, but there's a pond containing fish on the far side of the habitat, in case you have more carnivorous tastes."

I said, "Unfortunately you don't have milk, because we haven't added goats. They're far too destructive to let loose in here. They'd quickly destroy the habitat."

Sylvia shrugged, "No problem. We didn't have milk back in the barracks either."

Vincent said, "Another, much larger habitat began excavating next to this one around the same time this one started. It should be complete in about another month from now. You can decide what kind of environment you want for it. It could be a drier environment, suitable for growing grain. Or you could have an aquatic environment, which is the highest producing kind, but also the most difficult to balance. Or you could have a rainforest, which is also highly productive yet very stable, but takes quite a few years to really start producing. Or you could have another temperate environment, like this one. We'll help you set up whatever you decide on."

We took Sylvia and Ian on a tour of the habitat's garden, explaining what everything was and what they could expect of the plants and the trees eventually. Vincent showed how they could use a handheld computer to take a picture of the leaf of a plant so it could be identified using the main computer database. That would give them data on all known aspects of that plant. If they were unsure of anything, they should contact Dahlia and Matt, who had more practical knowledge about plants than anybody else in our community. Aimee could also help because she was able to access information in our computers more quickly and easily than anyone else.

Around mid-morning the four of us bid Sylvia and Ian goodbye, and we headed back home. We promised to bring them some horses on our next visit, just as soon as we built some more.

On the way home I remember wondering aloud what Sylvia and Ian would specialise in. All of us seemed to have various skills that we preferred. What would theirs be? It didn't take long to find out. I wasn't part of the team that later gave them the life-extension inoculation, and brought them better fitting suits, a couple of horses, and several drones, and instructed them on their use and features, but Sylvia and Ian were very quick learners, and soon put their new freedom and equipment to work freeing many more people from the military. It quickly became obvious we would have to rapidly expand the number of habitats to keep up with all the people that Sylvia and Ian convinced to defect from the military.

They became a major thorn in the side of the military. Many troops were sent out looking for them, with orders to kill them on sight. During this time some of us worried that the military had now been stirred up to become an even greater threat to us all, but after a couple of years of failure to deter Sylvia and Ian and their ever growing group of renegades, and seeing dramatically increasing numbers of people defecting, the military decided it was wiser to avoid us and we didn't see them again for decades.

I'd love to be able to say that all the new colonists in the new habitats enjoyed the same kind of non-hierarchical democracy we did, but sadly, it seems that's not how most people are. Many did see the sense in that way of life, but the majority of habitat groups formed less happy arrangements, at least initially.

Some ran under bullies, whose victims we had to again rescue and spirit away to new habitats.

Some groups formed rigid centralised structures, reminiscent of the old communist systems I'd read about. Those generally worked for a little while but inevitably degenerated into bully systems, and again, we'd have to rescue their disaffected workers.

Some groups started trading using some kind of tokens for money. Those always broke down after a while too, with a small number of people accumulating almost all the currency, taking advantage of bottlenecks in supply, and becoming yet another variant of the bully groups again, often destroying their habitat's ability to support them and then going out on forays attempting to steal and exploit other groups' habitats. When they tried that we "grounded" them, took back their horses, and explained via the comms system how to repair their own habitat.

Some groups, astonishingly, set up copies of the old military system they'd escaped from (try to explain the sense behind that!) and we had to free the unwilling underlings... again! In those cases, like so many of the bully systems, we had to confiscate their horses because they inevitably began raiding other habitats for resources and slaves.

We even had a few cases of religious cults developing! It was very difficult to know what to do to in those instances because most of their victims didn't want to be rescued. It was difficult to sit by and watch that abuse. We only really intervened when they tried to go out and indoctrinate others or when they destroyed their own ecology, both of which almost always ended up occurring.

We carefully explained again to people escaping bully systems that their habitat was almost self-maintaining. There was very little they needed to do. They could even let their habitat run completely wild and it would still support a small number of people indefinitely. There was no need to ever owe anybody anything — no need for anybody to be forced to do anything by anybody else. Unfortunately there seems to be some fundamental flaw in the human mind that causes some people to want to dominate others, and a reciprocal belief by many others that they need to be told by the dominant ones what to think and do. I don't understand it. Even now, all this time later, I still don't understand it. How hard is it for people to simply respect each other and work together as equals? It's a mystery to me.

I had felt that our way of living was something new to humanity, but Jill, always more wise in such things than I am, disagreed. She pointed out that the old open-source movement had worked the way we do, with people creating things because they wanted to — "to scratch an itch" as they used to say — instead of being forced by others, and that was undoubtedly the reason for the great success of open-source. Likewise, the great flowering of people creating webpages and videos and audio on the old internet was mostly because people simply wanted to. She also pointed out that all over the world, before the catastrophe, scientists worked and shared with each other, regardless of national boundaries, language, race, or any other artificial division. It was natural that, coming from a scientific community, we would inherit this way of thinking. She's right, of course. Science was not a political movement — it wasn't constrained by borders. Human creativity and the desire to learn are far more effective than any political system.

I didn't accompany Sylvia and Ian on any of their adventures, so I won't say much about their thrilling exploits. Sylvia is compiling an account of those events, so I'll leave that to her.

There was less and less need for me to be involved in explorations. I was increasingly reluctant to leave our Habitat, and found more excuses to stay home with Jill. Even when we organised a major expedition to the Australian Grains Genebank at Horsham, in Victoria, I preferred to remain home. The purpose of that journey, by the way, was to find out if the seed bank had survived the catastrophe. Sadly, it had not. The builders had constructed it above ground, where it had been difficult to protect from the elements. Before the catastrophe it had been converted to run on solar and wind power, independent of the electricity grid, and someone had clearly survived the catastrophe for many years there, living in the place and maintaining the machinery. They had either abandoned it, or died during a foray outside, and it had eventually fallen into disrepair. The power supply no longer worked reliably since the batteries had long since died. The cooling system had broken down and the seed banks had almost all spoiled. The exploration team did manage to salvage some seeds, but they were mostly more hardy native plants, not many food crops. That was very disappointing to us all. We had hoped for more diversity in our food supply to come out of that expedition.

It was about this time that Aida, on her journey to Montreal, reached Napier, in New Zealand. I won't spend a lot of time describing Aida's adventures. Her wonderful written works and videos are available in the library, so I'll only give a quick overview here.

Aida had much better luck than the team who went to the Genebank. The group of scientists in the National Aquarium in New Zealand had sustained a very wide diversity of fish, shellfish, octopus, corals, and other marine organisms in the expanded National Aquarium. They even had some fresh water fish.

She delivered an encryption code to them, letting them communicate more freely with us, but of course was unable to bring any creatures back to us as she then departed on the long journey to Montreal. (We would later send a much larger ship piloted by Ailis to our friends in New Zealand, giving them our technology and some plants, and bringing back lots of specimens for our habitats.)

Aida spent a couple of months with the folks in Montreal, though of course she was unable to venture into the undergound city because her body was limited by the radio link to her brain onboard the ship.

After that she once more rode the currents across the North Atlantic to Norway. She found the Global Seed Vault at Svalbard. None of us expected it to have survived intact, especially after the experience at the Australian Grains Genebank, but amazingly, it was still functioning. Some far-sighted administrator had changed the installation's power source over to geothermal, and even though the permafrost had all thawed, the refrigeration equipment was still, unbelieveably, humming away. Entering the place was not easy, but Aida was persistent and eventually non-destructively opened the doors. When she was satified that the seeds inside were unharmed, she closed the place up again and sailed south to Norway, specifically to the city of Trondheim, then up the river, Nidelva, almost to the Cryogenetics laboratories at Sjetnemarka. She was able to sail past the first dam, which had broken and eroded away, but the second was still standing. However at that point she only had to walk about 500 meters to the lab. There, she was able to find portable refrigeration equipment that she could use to transport the seeds back home. While she was there, she found, to her great surprise, that they also had many species of fish eggs stored there in equipment that was still functioning. She brought some of those back to the ship too.

After returning to Svalbard and making a wide selection of seeds, she set out for home, returning across the polar sea, no longer covered in ice, through the Bering Strait to follow the western side of the Pacific, down to Japan.

Japan turns out to have been one of the few countries in the world that had infrastructure allowing great numbers of people to survive the catastrophe. Their far-sighted scientists, technologists and business people had pushed for the construction of enormous underground cities in many of the major centers. Originally motivated by the scarcity of land and its high cost, they began building undergound shopping malls, as many other countries had, but they took it much further, embarking on the construction of an extraordinary network of underground cities, collectively called Alice Cities. Their scientists were respected and listened to by their politicians and business people. So, when the catastrophe did arrive, they were probably the only nation that was relatively well prepared. Millions still died, but hundreds of thousands survived in those underground cities. They were mostly built under the major business centers, which had become flooded by the rising ocean, however the underground cities had survived. They'd already been built below sea level. The greatest challenge had been to seal off entries that posed dangers. They could still access the surface from places that remained above the waters.

During her approach, Aida had made contact with them via radio and sailed to one of the largest underground cities under what had been Tokyo, which had now become a bay. She moored at the new coast, originally the foothills surrounding Tokyo, and met an excited, waving, smiling group who welcomed her from behind the glass doors of an airlock. She entered and they proudly wanted to show her their city. As she had done in Montreal, she politely declined, explaining that she was unable to venture far from her ship, as it contained her mind. She gave them the encryption key for secure communications and promised that others would follow to bring lots of cool technology, and plants, and animals for them. They reciprocated, promising to share their technology in return.

Aida wanted to visit Shenzhen in China, because she'd been in contact with them for many weeks. They had a very large underground city filled with wonderful technology, but unfortunately the prevailing winds made sailing there from Japan very difficult, and her inability to venture far from the ship made it impractical anyway, so she assured them that she, or someone else from here would visit in the very near future, and she headed home.

At that point Aida had been away for a few years and Ailis had already left in a much larger ship, on her decades-long journey to carry gifts to people Aida had already met, and to explore further inland in many places around the world.

For Aida's return, a crowd of us journeyed in our horses to the coast to greet her. We waited at the water's edge a little south of the bay that had once been Maroochydore. Sitting in our horses we chatted via radio with Aida and with each other. We had been watching her kite-sail approach for perhaps an hour before we were able to see the rounded top of her ship, just barely peeking above the grass-green waves. A cheer went up from us all.

Aida's response, "That was very loud" brought laughter from us.

When she came close to the shore she reeled in the kite and drove using the wing-like side fins of the ship. Ben and Maria jumped onto the edge of the ship, which was knee-deep under the water, and pulled the docking cables out of their inset housings on the ship, then, jumping back to the shore, secured the clasps on the ends of the cables to trees near the shore. The cables then tightened, as the ship winched itself up firmly to the land, with the near, front edge above the water.

The hatch on top of the raised center swung open and Aida emerged and walked across the ship, onto the shore where each of us hugged her, telling her how glad we were that she was back. Kayla and Amiee went onboard the ship carrying tools and a powerpack. They reappeared soon after, carrying the large box that housed Aida's mind.

Blossum beckoned Aida, "We have a party and a surprise waiting for you at home."

Aida held up her hand, "Wait. I need to bring some things from my travels. They're too heavy for me to carry alone..." Ben volunteered to help, and went back into the ship with her, re-emerging minutes later awkwardly lugging some large cases.

When Aida, her brain, and the two cases were safely stowed in the luggage compartments of our horses, we started back the way we'd come. First, we walked our horses along the shoreline cliffs a little way north toward where the hills gave us easy travel west. We were still travelling north when Jill called out, "Wait."

We all stopped. Jill was pointing at the broken remains of a road that curved toward the cliff to our right. She sqatted her horse down, wriggled out into her suit, and detached to walk toward the crumbled road.

Puzzled, I did the same, and followed her. "What is it?" I asked.

She waved her arm in a wide sweep indicating the roadway, the cliff, and the undulating bright green sea far below us. "Do you remember that day we first found out we weren't alone? This is the spot where your journal started. We were standing here... well, actually a little further down the road." We looked at where the road had now been eroded away completely. "We were feeling awfully hot, and sweaty, and discouraged in the face of a dark, bleak world and decided to head home early."

"I remember." I put my arm around her. "Everything's so different now — our lightweight, insulated, cooled suits, real hope for the future, part of a team, surrounded by friends."

She put her helmeted head on my shoulder and whispered, "No longer restricted to roads... riding in amazing mechanical horses. Remember our little hatchback Tesla?"

I nodded. "Mmm. Our family has grown so large... and now we know survivors exist all over the world. Who knows what the future will bring?"

Kayla, still seated in her horse, behind us, broke our thoughts, "Well, there's one thing we can be pretty sure of: there will be no civilisations on other worlds visiting us."

This comment was so out of step with everything, Jill and I turned toward Kayla. It was like in those old movies, where the orchestra swells warmly, and then something suddenly interrupts and the needle scratches across the record. Jill laughed, "What?"

Kayla said, "The Fermi Paradox is not a paradox," as if that was supposed to mean something to us.

Gabriel explained, "The Fermi Paradox is the puzzle of why there seem to be no alien civilisations despite the overwhelming number of star systems seemingly making it almost a certainty that they must exist. What do you mean Kayla?"

She said, "It's pretty obvious. Normally, advanced animal life will never develop because plants would tend to evolve the most efficient metabolic pathway early in a world's history. Animal life on Earth survived despite overwhelming odds; if the more efficient plant metabolism had developed billions, or millions of years ago, or even just centuries ago, there would be no animal life on Earth right now, except for a few primitive, anaerobic forms. We are almost certainly all there is... in our galaxy, at least."

This was such a strange comment from Kayla, who was normally so reluctant to speak, I had to resist the urge to laugh. I looked at Jill. Behind the darkly transparent faceshield of her suit she was grinning widely. I tried to imagine centuries of being loved by her, and said, "Well, if this is all there is, then." And we hugged. I could hardly wait to get home where we were not separated by suits.

— END —

This story didn't cost you anything to read, but took me years to write. Please, please send me some kind of feedback, letting me know what you thought of it. All comments will be gratefully received.