Proxima

Chapter 39 2180

The ColU, which was becoming increasingly philosophical as time passed, came up with yet another complex, bewildering observation about life on Per Ardua.

At the time Yuri was letting Beth ride on the ColU’s back with him, on the final fifty-kilometre round-trip trek to the old camp from the new. He’d thought the ColU had been acting oddly all day, but had put it down to the usual program-violation problems it had with moving the camp in the first place. Evidently not.

Luckily Beth was oblivious to all this. Beth Eden Jones was seven years old now, and she had been used to moving all her life. The first shift of the jilla had come in the very month she had been born, and there had been seven shifts since then, around one a year, bringing the lake the best part of two hundred kilometres due south from the starting point. The family had diligently followed along each time, hauling their broken-down dwellings and their tools and all their other possessions, right down to cartloads of topsoil, behind the patient bulk of the ColU.

But the last shift had been all of a year ago, and since then some spark in Beth’s head had lit up. This time she wasn’t a passive passenger any more; now she wanted to make sense of it all. So she had begged to come along on these shuttle trips back and forth between the old campsite and the new. Mardina was happy to let her ride along with Yuri—especially as it got her out of the way while the builders completed their latest brutal war of conquest against their cousins at the jilla’s new position. But on this ride, this last loading up, Beth was fretful.

As soon as they were loaded, the ColU had begun the last haul away from the old campsite, of which little was left but a scuffed patch of ground, a smouldering fire, a couple of garbage dumps, all set beside a muddy lake bed that was already drying out. They headed south once more, following the water courses down which the builders had driven the waters of the jilla. And, wistfully, sitting beside her father on the carapace of the ColU, Beth looked over her shoulder back the way they had come. “Why can’t we ever go that way, Dad?”

“What way, honey? North? What’s the point? There’s nothing there. There’s not even water to drink.”

“I know. But there’s the first camp of all, isn’t there? Back there somewhere.”

“Where you were born.”

“I know that. But I don’t remember it.”

“It’s too far. There’s no water on the way. We couldn’t walk that far.”

“We could ride on the ColU,” she said hopefully. “We could carry water. We could carry our beds and stuff, and Mister Sticks.” Mister Sticks, her favourite toy, had been woven from broken stems by the ColU; the doll was a peculiar mix of human and builder features, like a three-legged puppet.

“That’s not a bad plan, honey. But the ColU wouldn’t carry us that far.”

“It could, though.”

“But it wouldn’t. It… doesn’t want to.”

“You could make it.”

“Only by hurting it. And that would be mean, wouldn’t it?” Which was about as close as he imagined he was going to get to explaining program conflicts in the ColU’s AI to Beth.

“I guess…”

“What do you want to see up there anyhow? It’s just like all the other places we stopped. Just a load of old junk that we dumped when we moved. Abandoned fields…” And a few graves.

“But I want to see the road where the shuttle came down.” She mimed a descending flight with her hand, but she made a noise like the flapping triple vanes of an Arduan kite, the only flying thing she had ever seen. “Flish-flish-flish. Mom says it made tracks that would take you hours to walk along.”

“I guess so. Skid marks kilometres long. And some of it baked solid, when the braking rockets fired. I guess that would be worth seeing, if it’s still there. But we can’t get there, honey. I’m sorry.”

“Maybe one day.”

“Well—”

“Take me there for my birthday one day.” That was Beth’s trump card.

Her birthdays were an issue. Yuri had been slow to realise that even after Beth’s birth Mardina had clung to her belief, or fantasy, that the ISF had never really left, and would some day come out of their hides or down from orbit or whatever, and reveal themselves, and save them all. Maybe the baby being delivered would be the trigger, if the ISF authorities accepted that the colonists had proven their determination to stick it out by breeding. Well, that hadn’t happened. She’d not mentioned it at the time of the birth, and Yuri forgot about it.

But on Beth’s first birthday the dam broke, and Mardina went into a rage at a betrayal that, at last, she couldn’t deny. It caused a lot of tension. It was still a birthday. Yuri had tried baking a cake, with butter and stuff from the iron cow unit inside the ColU. The ColU had even made candles from synthesised fat. Mardina ruined it all. Beth had been too young to understand, but for Yuri, the memories of The Day Mommy Lost It remained strong.

The next year, with Yuri gently prodding, they had agreed they should celebrate the birthday. After all Beth didn’t have other kids around, she was never going to go to school or college or enjoy all the other milestones regular children did, even in a dump like Eden on Mars. A birthday, though, one thing that was uniquely hers, could always be marked and celebrated. And, as a tie to the cycles of time on Earth, it was a reminder of deeper roots too. But by the time that second birthday rolled around the echoes of the first were still strong, and Mardina withdrew into herself.

Well, since then they had celebrated all Beth’s birthdays, but there was always tension. And Beth, with a little kid’s wiles, picked that up and played on it. Yuri just coped with it all. Nobody had ever told him life was going to be easy.

“Listen, it’s late, why don’t you take a nap? That way you’ll be fresh for Mom when you get home.”

“I don’t want to take a nap.”

“Just try,” he said in his line-in-the-sand voice, much practised over seven years.

So she complied. She wriggled inside her rope harness until she was lying down on a couple of blankets, and cuddled up against her father’s leg. He put one arm around her and stroked her short-cut straight hair with his free hand. They had had trouble with her sleeping from the beginning. Born into the endless day of Proxima, she seemed that bit more disconnected from the rhythms of distant Earth, and didn’t see why she needed to go to sleep when her parents did, at what seemed like arbitrary times in the unending light. But if they let her get away without regular sleep she would burn herself out and crash, so Yuri and Mardina had worked out a process of control between them.

Even the ColU, which had some programming in child care, was drafted into this regime. It always backed up the parents’ diktats, which was just as well, Yuri thought, or it would have found Mardina decommissioning it enthusiastically. The ColU was the third “person” in Beth’s limited life, and she saw nothing strange in having a robotic farming machine as a kind of uncle. Proving to be an expert at weaving dolls from dead stem shafts didn’t do its image any harm either.

Soon Beth was asleep; she had a soft, gentle snore.

Yuri had time to inspect the route they were following. After all, it was the last time he expected ever to come this way. The ColU was following its own tracks along the bank of a broad, braided river bed. Like most of the channels down which the builders guided the flow of their lake this bed had been here already, but was dry as bones before the lake came. Now the bed was littered with the detritus of the passage of the waters of the lake: snapped stems, a few broken builder traps, dead aquatic creatures from fish analogues to crab analogues and jellyfish analogues, and others they had yet to identify. There was even some terrestrial-origin seaweed, the gen-enged laver brought to this world by the starship Ad Astra.

After years of observation, even the ColU had no real idea how the builders managed these hydrological transfers so effectively. The lake stayed in stable locations for months or years at a time—it had turned out that the site where the shuttle had landed had been the longest stay so far, and in fact the intervals between moves were generally getting shorter. It was clear the builders used existing water courses, although they would sometimes dig out or extend canal-like connecting passageways, and their characteristic middens were used to guide the flow of the water precisely where they wanted it to go.

And, wherever the lake finally pooled, there were always local streams and springs to feed it. The mystery of that was that as the land’s wider uplift continued—and the ColU constantly reminded them that some dramatic geological event was apparently unfolding to the north of here—the pattern of the region’s springs changed all the time, as underground aquifers were shifted or broken, the water tables realigned. The builders always seemed to know in advance where the useful springs would be, and how to re-establish the lake. The builders didn’t have maps, but they evidently knew about geography; they must be able to visualise the landscape in some way.

It was as Yuri mused on this that the ColU’s theorising broke into his day.

The ColU jolted to a sudden stop.

Beth muttered and stirred. Yuri stroked her head, and she calmed again. He looked around. There was nothing special here, no obvious reason to have stopped.

The ColU backed up a little way, then rolled forward with a grinding of ageing gears. Again Beth stirred, before settling.

Yuri whispered urgently, “Hey! What’s wrong with you?”

The ColU’s voice was a matching whisper. “Yuri Eden?”

“Why have you stopped? Get going before this one wakes up, or Mardina will slaughter the lot of us.”

“I am sorry. I had not realised I had stopped.” It rolled on with a sight lurch.

“So what was all that about?”

“Yuri Eden, call it an existential crisis.”

Yuri groaned inwardly. Not again.

He knew he’d have to tell Mardina about this episode, whatever it was; she was concerned about anything erratic in the ColU’s behaviour. The ColU had made it clear from the beginning that to have been forced to help transport the colonists across the planet, if they’d attempted to escape from the landing sites that had been planned for them by the starship crew, would have violated its deepest layers of programming. So when the lake had first shifted, in its algorithmic soul the ColU faced a conflict between mandates to keep its human charges alive, and to stay close to the original landing site. The preservation of life had won out. But Mardina, who knew a lot more about ISF AIs than Yuri did, fretted that some deep internal damage might have been done. All of which was over Yuri’s head, let alone the head of his seven-year-old daughter, his little muda-muda.

Now, reluctantly, he asked, “What existential crisis?”

“I have come to a conclusion which baffles and alarms me. I have just received, from my internal laboratory facilities, the results of the analysis of a novel organism which enabled me to complete a genetic mapping—you’re aware that among my long-term projects has been the construction of a tree of life, for the Arduan native flora and fauna—”

“You know, I wish I just had a truck.”

“Yuri Eden?”

“Like the rovers on Mars. A truck I could just drive. The number of conversations like this that I’ve had with you over the years—”

“I can’t help it,” the ColU said, sounding almost miserable. “I can’t constrain my curiosity. Nor should I. Until my understanding of this world is complete enough—”

“Just tell me.”

It paused, as if gathering its thoughts. “Yuri Eden, I have told you that life on this world is similar in its fundamentals to life on Earth, but not identical. I believe the two biospheres may be linked by a panspermia process that operated at a very early date. The earliest days of life on Per Ardua might have been like the early days of Earth, a world of simple bacteria, drawing their energy from chemical reactions in the rocks. But all the time much more energy, a hundred times as much, was available, washing down from the sky—”

“Proxima light.”

“Yes. The next step was the development of kinds of photosynthesis, creatures that could draw energy directly from that light. The new kind colonised the surface, while the older ones survived, sinking deeper into the planet. And there they still reside in great reefs, in caverns, in porous rock and aquifers, dreaming unknowable dreams. Just as on Earth, life on Per Ardua is actually dominated by the bugs in the deep layers, mass for mass. But on the surface, as photosynthesis evolved, ultimately oxygen was released as a byproduct.”

“Like the green algae on Earth.”

“Yes, Yuri Eden, this step, oxygen production, was evidently difficult to achieve; on Earth it occurred only once, and in fact came from the coupling of two older photosynthetic processes. I have yet to fully understand the equivalent process on Per Ardua—it is necessarily different because the energy content of the light here is heavy in the infrared—but it is evidently just as complex, just as unlikely to have happened.”

“Yet it did happen.”

“It did, and I have been able to date the event from traces in the Arduan genetic record: some two billion, seven hundred million years ago.” It paused. When Yuri didn’t react it went on, “The next great step in the emergence of Arduan life, again mirrored on Earth, was the development of a new kind of cell: a much more complex organism, a cell with a nucleus, a cell with different kinds of mechanisms within a containing membrane. Of course the energy available from burning up all the oxygen concentrating in the air helped with that. Such complex cells are the basis of all multicellular life, including you, including the builders. This was an information revolution, not a chemical one; these complicated creatures needed about a thousand times as much genetic information to define them as their simpler predecessors.”

“Another unlikely step.”

“Yes. But again it occurred on both worlds. And on Per Ardua this came about some two billion years ago.” Another pause. “Yuri, I am not sure you are grasping the significance of—”

“Just tell me the story,” Yuri said. He stroked his daughter’s hair, growing sleepy himself.

“Multicellular life emerged some time later—evidently another difficult step to take. Seaweeds first on Earth, like the lavers we imported to Per Ardua…”

The new camp was coming into view, the lake settling into the contours of its latest shoreline. Yuri saw builders busily working all around the lake’s edge, and smoke rising from Mardina’s camp fire.

The ColU was still talking about ancient life. “Of all the great revolutions of life this is the easiest to identify on Earth because it left such clear traces in the fossil record. On Per Ardua, of course, there is no fossil record to speak of. And yet—”

“And yet you, through heroic efforts, have worked it out anyway.”

“I’m just trying to explain, Yuri Eden.”

“All right.”

“Yes, I have seen traces of this event in the genes, and also in some fringe organisms that have survived on Per Ardua to this day. And—now this is the significant point, Yuri Eden—I have established that all this occurred some five hundred and forty-two million years ago. Do you see? Do you see?”

“See what?” Beth sat up now, rubbing her eyes. “I smelled smoke in my dreams. I thought the ColU was on fire!”

“No, honey, it’s just the camp fire.” Yuri didn’t see the ColU’s point at all, he couldn’t care less about such abstractions, and as the unit rolled into the camp the conversation was already fading from his mind. “Go find your Mom, sweetheart, and I’ll help the ColU get everything put away safely.”

Chapter 40

Mardina prepared lunch.

It was a kind of quick picnic assembled from chuno. This was a long-lasting paste you could make from potatoes by freezing, thawing, desiccating them—a smart trick from the Andes that the ColU had taught them, and invaluable for their travelling phases, but the result was a greyish muck in appearance that Beth had always cordially hated. But today she was hungry after the long journey back to the camp, and excited about the move. Certainly she didn’t want to sleep any more. They all had a peculiar mixture of tiredness and energy, Yuri thought, like they had gone on vacation maybe.

They decided to take the rest of the day off, and go exploring. The ColU, after trying to speak to Mardina about its mysterious science conclusions, grumpily rolled away and began the process of unpacking its last load from the old camp, including another tonne of terrestrial topsoil.

The family walked to the lake’s latest location, with Beth skipping ahead, and Mardina and Yuri side by side.

The ground in this country, away from the lake and the water courses, was as arid as they had ever experienced it. In fact, Yuri suspected the landscape was becoming drier, hotter, the further south they travelled. Which made sense; the further south you went and the closer to the substellar point you reached, the further Proxima rose in the sky, and the more heat it delivered. Yuri still had the map Lemmy had compiled from the colonists’ remembrances of the shuttle flight, before they’d all killed each other, and that showed concentric bands of climate and vegetation types around the substellar. If they walked far enough, Yuri supposed, they would in the end reach true lifeless desert, surrounding the substellar point itself, which the ColU predicted would be the site of a permanent storm system. Even before that, maybe there would come a point where the ground was no longer habitable for them at all. But they were following the builders, who had evidently been going through this process for uncounted millennia, and Yuri and Mardina had decided to trust them—well, having followed the jilla this far, they had no choice.

They came to the lake shore, a fringe of muddy ground with banks of new stems growing vigorously. The stems seemed to be self-seeding, but the colonists had observed the builders practising what looked like simple agriculture to help the stems along, planting shoots, irrigating the mud with crude drainage ditches. The water itself was still turbulent and turbid, not yet having settled into its new bowl. Around the shore of the lake Yuri could see builders working, setting up what looked like a nursery area with the outlines of domed shelters rising up from the debris—and already assembling basic middens, in preparation presumably for the next move of the jilla.

But there was another area where builders, adults and children, had been herded in a huddle, surrounded by others that spun and whirled around them. One by one the prisoners were taken out to an area where more builders pinned them down and, brutally, crudely, disarticulated them, taking away their constituent stems to one of the new midden heaps. It looked like a prison camp crossed with an open-air operating theatre—or, perhaps, like some appallingly brutal schoolyard game being played out by stick puppets. The sound of the continuing murders was an eerie rustling, a clatter of sticks, the scrape of sharpened stone on stem bark.

Yuri and Mardina gently guided Beth away from the scene. They had seen this many times before: it was the aftermath of a builder invasion, of conquest. There had been another community of builders here, living in the formerly dry lake bed, happily feeding off the local springs and stems—before the jilla folk arrived, brutally evicted them, flooded their homeland, and massacred any survivors.

Beth hadn’t yet worked this out. Now, luckily, she spotted the nursery and ran that way to see.

“The same every time,” Mardina said, looking back at the slaughter yard. “And I used to think the builders were cute…”

Yuri said, “They’re little wooden Nazis. Some day we’re going to have to explain all this to Beth, you know.”

“Genocide in Toyland. There’s never going to be a good day to talk about that. Maybe you could tell her about your Heroic Generation at the same time. Give her some context. It’s not just builders that behave this way.”

“For the thousandth time, it wasn’t my…”

But of course she was only goading him, for the thousandth time. She asked, “What did the ColU want to talk to me about, by the way? Seemed very intense.”

“Oh, one of its theories. Life on Per Ardua. It seems to have got a pretty good family tree for this world now. Lots of bragging about genetic comparisons and stuff. He’s identified major revolutions in the story of life here.”

“What revolutions?”

Yuri thought back. “Photosynthesis, I mean a fancy advanced kind that produced oxygen as a waste product. Then complex cells, with nuclei. Then plant and animal life. The ColU got worked up about the dates it’s established for these events. Meant nothing much to me.”

“What dates?”

He concentrated. “Photosynthesis two point seven billion years ago. The complex cells two billion years ago. And the animals—umm, five hundred and forty-two million years ago, I think.”

Mardina stared at him.

Some distance away, at the fringe of the trodden mud around the new lake, Beth had found something worth shouting about. She jumped up and down, waving. “Mom! Dad! Come see!”

Mardina called, “OK, sweetie.” They began to walk over. “Yuri—are you sure about those dates?”

He felt uncertain, now she pressed him. “Well, I think so.”

“It’s just—I’m no expert, but I took terraforming modules during my ISF training, and we studied the history of Earth life, the key transitions. Yuri, the dates for the similar events on Earth are: two point seven billion years, two billion years, and—”

He guessed, “Five hundred and forty-two million?”

“Yeah. I mean the last particularly is pretty precise, from the fossil record on Earth.”

“Mom! Dad! Come see, before it all gets trampled!”

Mardina said, “Life on two worlds separated by light years having a common sugar base—well, you can wave your hands about panspermia to justify that. But such a precise coordination of the key dates of all those improbable events?”

“What does it mean?”

“Damned if I know.”

“Mom! Dad!” Beth, quite agitated, was almost screaming now.

And when Yuri and Mardina finally got there, at the edge of the pond’s muddy fringe, they could see immediately why.

Beth had found a human footprint.

Chapter 41

The invitation from Earthshine reached Stef at her workstation in the UN kernel lab on the moon.

In a short, low-res holographic message—a cube showing his well-groomed head, his smiling middle-aged-politician-type face—the Core AI requested that she come visit him on Earth, at what he called his “node” in Paris. He said he had a matter to discuss of global importance, but specifically of interest to “you and your sister”. There was also an avowal, in legal wording, that the AI would make no attempt to access the growing knowledge base on kernel physics during his meeting with the sisters. Without that avowal Stef supposed the message would never have been allowed through the various layers of security that surrounded her, here at Verne.

A similar message, an attachment noted, had been sent to Penny on Mercury.

Stef shut down the hologram with a curt acknowledgement of receipt, and spent a full dome-day thinking it over. That was her way when faced with dilemmas she found difficult or personally unpleasant, a way she’d developed of managing her own instincts over nearly thirty-six years of life. Let the news work its way through her conscious and subconscious mind, before formulating a decision. She even slept on it.

For one thing there was the sheer time she would need to take out of her own programme. Right now Stef was in a work jag that she was reluctant to climb out of. Well, she was always in a work jag. Seven years on from the Hatch’s first opening and the Penny incident—as she thought of it—explorations of the Hatch and investigations of its physical properties were shedding some light on the complementary studies of the kernels that had been going on for decades now. It was a slow, painstaking process, and it was full of gaps. Stef had the feeling she had been handed the two ends of a long chain of discovery, and she had a way to go before she worked her way from either end in towards the centre. But it was absorbing—there was more than a lifetime’s work here for her and her colleagues, she was sure. And that was a pleasing thought, since it pushed the need to make any drastic decisions about her own future off beyond the horizon.

Decisions such as about her relationship with her sister.

There was another reason for her to be wary about Earthshine’s note. She was actually working now with Penny. Her sister, who was on Mercury, was running direct experimentation on the Hatch emplacement, trying to detect emissions of various exotic high-energy particles. Unlike some siblings, indeed some twins, the sisters worked well together, as a long string of academic publications to their individual and joint credit from the beginning of their careers proved. In this particular project at this particular time Penny was the experimentalist, Stef the theoretician, but on other projects in the past, the record showed, it had often been the other way around. They were flexible that way, with close but complementary skill sets.

It was all fine and dandy, a family relationship to be admired and envied, and something that both their father and mother would have been proud of. It was just that Stef had no memory of any of this before the damn Hatch on Mercury had opened.

The news of the discovery had quickly leaked, and the Hatch had been a sensation for about twenty-four hours. It was after all evidence of alien intelligence in the solar system. But a Hatch leading nowhere had since been largely forgotten, or dismissed as a hoax, though it still trailed conspiracy theories like a comet tail.

But Stef was left with a massive rewiring of her own past.

Before the Hatch, she had been an only child. After it, suddenly she had a twin. Not only that, she suddenly had a whole different lifetime behind her, intertwined with that of her twin. Papers that had been to her sole accreditation, for instance, were now under joint authorship with her sister. She’d read some of them; they were much as she remembered writing them, but not quite—not significantly better or worse academically—and there were others, reflecting bits of work she couldn’t remember, that she’d never generated herself at all.

Only Stef remembered her solitary past before. Nobody else. Everybody in her life, including colleagues she’d known since her graduate-student days, thought of her now as half of a pair, not Stef alone. Not even King and Trant, who had been there at the moment of transition, remembered the old timeline.

Not even Penny remembered it. As far as Penny was concerned, their joint careers had just carried on, after a hiccup as Stef had tried to absorb what had happened at the Hatch. To Penny, Stef was a sister who had suddenly developed a kind of selective amnesia.

And maybe that was what it was. Some kind of mild craziness, perhaps triggered by some bizarro radiation field leaking from the alien artefact into which she’d climbed. That was the simplest explanation, after all, that her own perception, her memory, was somehow faulty. Though she’d looked hard, Stef hadn’t found a single shred of evidence to contradict the reality of it. The alternative, that history had somehow been changed around her, that the fault lay in the external universe rather than in her own small head, seemed an absurdly over-elaborate explanation by comparison.

She didn’t believe that, however. She knew herself, she knew her past, her life. And this past wasn’t hers.

She’d learned not to talk about this, not to anybody—not after the first few minutes of utter bafflement, up there on Mercury, in her pressure suit, in the Hatch, facing a sister she’d never known existed, and everybody had stared at her in dismay as she babbled out her confusion. After all she’d rather be working on kernel super-physics than spend the rest of her life on medication and therapy intended to rid her of “delusions”. She wouldn’t even talk to Penny about it, despite her sister’s tentative attempts to break through the barrier. Stef had been very happy to see Penny posted to a different planet, happy to just get on with her work; at least the work had stayed a constant comfort.

But now here was this summons from Earthshine, evidently intended to bring the two sisters together.

It seemed to Stef that despite much study and commentary, even while everybody acknowledged their power, most experts were unsure what the real agenda of the Core AIs might be. The three antique minds, a legacy of a difficult past, had no formal role in human society, no legal status—no rights, in a sense. But everybody knew that human agencies, from the UN and nation states on downwards, had to deal with them. Their power was recognised the way you would acknowledge the power of a natural phenomenon, a hurricane; you couldn’t ignore them, but they were outside the human world. And unlike hurricanes, the Core AIs could think and communicate.

Now Earthshine had chosen to communicate with Stef and her sister. Why? That depended, Stef supposed, on Earthshine’s own agenda. Maybe Earthshine had some kind of insight to share. But did she want her personal tangle of a life to be unpicked by such a monster?

On a personal level she was repelled. But on an intellectual level she was intrigued.

She acknowledged the note, logged the trip in her personal schedule, and with relief went back to work.

Chapter 42

Stef Kalinski dropped from the moon’s orbit to Earth, following the usual leisurely three-day unpowered trajectory. At Earth orbit she had to wait a day before she was transferred to an orbit-to-ground shuttle, like a snub-nosed plane with black heat tiles and white insulation, its cabin crowded with passengers and luggage.

The little craft glided down through the air with looping, sweeping curves.

On its final track the shuttle crossed the eastern coast of South America, coming down towards a strip of flat coastal savannah. The land glimmered with standing water, flooded by the rising ocean despite crumbling levees that still lined the coast. This was Kourou, Guiana, the old European space agency launch centre, now converted to a surface-to-orbit transit station. Further inland Stef saw bare ground, scrub, some of it plastered with solar-collector arrays like a coat of silver paint. This site was only a few hundred kilometres north of the mouth of the Amazon. Now there was no forest, and the river was reduced to a trickle through a semi-desert.

Only an hour after landing at Kourou Stef was being bundled into a small aircraft for her hop across the Atlantic. Like the shuttle the plane was crowded, fully loaded before it was allowed to take off; these days transport was always communal and always crowded, planes and shuttles and trains and buses, minimal energy usage the key goal.

The plane, powered by turbos driven by a compact microfusion engine, leapt easily into the air. The sky beyond the small, thick windows turned a deep blue; the trajectory was a suborbital hop, and they crossed the Atlantic high and fast, heading north-east towards western Europe, Portugal and Spain.

As the plane dipped back into the atmosphere over the Iberian coast, Stef wished she knew enough geography to recognise how much of this coastline had been changed by the risen sea. Near the shore she saw vapour feathers gleaming white, artificial cloud created by spray turbines standing out to sea and deflecting a little more sunlight from the overheated Earth. The ocean itself was green-blue, thick with plankton stimulated to grow and draw down carbon from the air.

The plane banked and headed north, streaking at high speed through the air. Southern Spain, long abandoned to desert, was chrome-plated with solar-cell farms, and studded with vast silvered bubbles, lodes of frozen-out carbon dioxide. Once across the Pyrenees they left behind the mid-latitude desertification zone and the ground gradually became greener. But even in central France Stef glimpsed great old cities abandoned or at least depopulated, the conurbations’ brown stains pierced by green as they fragmented back into the villages from which they had formed. Over northern France the plane swept west, circled, and then descended into an easterly headwind. Stef saw something of the Seine, more abandoned towns on a glistening floodplain. Away from the river olives grew in neat rows on dusty ground, a sight you would once have seen in southern Spain, an agriculture suited to the new age.

At Paris, the big old airports were no longer in use. Instead, with a stab of sharp deceleration, they were brought down at a small airport in a suburb called Bagneux, just south of central Paris itself, a clutter of ugly twentieth-century buildings cleared in great stripes to make room for the runways. There was another brisk transfer made mostly in silence; there was no documentation, but every passenger’s identity, security background and infective status were seamlessly checked with non-invasive DNA scans.

Soon Stef was through the process, and found herself and her minimal luggage alone in a small driverless electric car that whisked her north towards the city centre. She’d not been to Paris before, and the cramped streets swept by at bewildering speed. Somewhere the Eiffel Tower still stood proud, but around her she saw only walls of ancient sandstone stained by floodwater. Although this was still the political capital of the country there were few people around. Wealthy Parisians had long ago decanted to the cooler climes of southern England—Angleterre as it was known now—and the poor, presumably, had died out or drifted away.

She glimpsed the Île de la Cité, standing in the turbid waters of the Seine, where the roofs of Notre Dame were plastered with solar panels. A huge banyan tree sprawled before the cathedral, rooted in the flooded ruins of surrounding buildings.

At last the car brought her to the Champs-Élysées, an avenue even a first-time visitor like Stef could not fail to recognise. There was a fair density of traffic here, and pedestrians hurrying beneath sun-shade awnings. The car stopped outside a high, elaborate doorway, where a man stood in the shade, beside a slim woman in the uniform of the ISF. The man, of course, was Earthshine. And the woman was Penny Kalinski, Stef’s impossible sister.

Earthshine, who cast a convincing shadow when he stepped into the light, bowed to Stef as she climbed out of the car. “Greetings,” he said in his cultured British accent. He made no attempt to shake Stef’s hand, but wafted his fingers through the lintel of the doorway; pixels scattered from his fingertips like fairy dust. “At least in European manners, this is how to announce one is only a virtual presence. I hope this suit—that’s how I think of my various bodies, as ‘suits’—is acceptable to you both.”

“It’s fine,” Penny said. She was looking steadily at Stef. Then she approached her sister, one pace, two.

Stef stood rigid, almost at attention beside her luggage, unwilling to respond. There was a stiff moment.

Penny said, “Here we are, in person together, for only, what, the fourth time, the fifth? Since—”

“Since the Hatch opened.”

“Right.” Penny stepped back, subtly. “Sorry. Old habits die hard. Even after all this time. We always hugged, before.”

Earthshine watched this exchange with lively interest. “The ‘always’ applies to you, Penny Kalinski. To what you remember. But to your sister Stef, the ‘always’, the past before the Hatch incident, did not include you at all.”

“That’s right,” Stef said. “Lucky me. Suddenly I gained a sister.”

A look crossed Penny’s face, like the passing shadow of a defunct Heroic Generation sunshield. “And I,” she said, “feel like I lost one.”

“Fascinating,” murmured Earthshine. “Fascinating. But here we are standing in the heat. Please, come into the shade, both of you…”

The old building extended to several storeys and an underground extension. For Stef, the most striking feature of the ornate interior was a sweeping marble staircase down which the virtual projection of Earthshine marched with convincing footfalls, his shadow shifting in the soft lighting. “Once this was an Italian-owned bank,” he said, “but it has been put to many other uses over the centuries. Including a bookstore, when they still had paper books. A real historical relic…” Cleaning robots worked discreetly.

They reached a relatively small, cool, windowless, underground reception room, where Earthshine invited them to sit on overstuffed armchairs, and offered them water, American-style soda, coffee, from a self-service counter. Penny took a coffee, Stef a glass of water. The room was without decoration, save for a big block of what looked like sea-eroded concrete on one wall, maybe half a metre across, its deeply pitted face marked with a mesh of concentric circles and arrowing lines, apparently intentionally carved. Stef remembered a similar design on a brooch Earthshine had worn before. The peculiar item distracted her; it looked elusively like some kind of map, a schematic, but she could not have said a map of what.

“So,” Earthshine said, sitting with legs crossed, fingers steepled. “It’s good of you to have come so far to meet me—and to take a break from your work schedules, which I know is a sacrifice for both of you. Thank you too for agreeing to put up with each other’s company, at least for a short while. Welcome to my underground lair! Or one of them.” He smiled, with a show of apparently charming self-deprecation. “That’s how you think of us, isn’t it? Terrible old monsters, ruling the world from our furtive dens.”

Stef said, “I like to think we’re a bit more sophisticated than that.”

But Penny countered, “No, you got it about right.”

Earthshine grinned. “You contradict each other. In your talk, even in your choice of drinks. Whatever one does, the other must not follow. How fascinating. And yet by behaving this way you become ever more the mirror images that you each appear to reject…”

For Stef all this was picking at a scab. She snapped, “Is there a point to this?”

“Oh, indeed there is,” Earthshine said. “In fact your oddly coupled nature is what I primarily wish to talk to you about. I have followed your trajectories since that strange day on Mercury when the Hatch was opened. Well—you won’t be surprised to learn that. It’s what you would expect of me, isn’t it? To watch over you all, like some inquisitive god.” He leaned forward. “I have asked you here, you see, because I have learned something. I have found something.”

“Something to do with us?” Stef asked.

Penny said, “And what’s it to do with you, Earthshine? What do you want?”

“Well, that’s rather nebulous at the moment. Suffice to say—” He paused, as if choosing his words. “I want to stop being afraid.”

Stef stared at him, startled by that peculiar non sequitur. He’d said this calmly, his expression still, faintly artificial. Yet that, somehow, made it all the more convincing.

Penny seemed more aggressive. “You, afraid? Afraid of what? You’re an artificial mind stored underground in massively paralleled and distributed processor and memory banks, with your own dedicated manufacturing units and energy supply. You and your partners rode out the climate Jolts like they were bumps in the road, while millions of us died. What could you possibly be afraid of?”

“I will explain, in time.” He held out his hands. “I know this is difficult for you. But here you are, together. Would you like to talk?”

Penny and Stef looked into each other’s eyes, just as they had in that first moment of revelation in the Hatch on Mercury. Then they looked away.

At length Stef said, “I’ve done some research. On us, on our past.”

“I know. You’ve been doing it for years. My firewall traced you. I let you go ahead.”

“I saw the records,” Stef said. “As they exist now. We are twins, genetically identical. I am the older by a few minutes. We seem to have been close companions when we were small.”

“I remember,” Penny said more softly. “I wouldn’t need to research it. We played all the time.”

“We were put through the same schools by our father. We showed the same kind of aptitude, basically mathematical, logical, verbal. We both joined the ISF for the sake of scholarships that put us through grad school and sponsored our early researches, and enabled us to get access to the kernel labs on the moon.”

“The ISF split us up,” Penny said. “Their psychs thought it would make each of us more self-reliant. Still we did the same training and development, more or less, just in a different order.”

“But our careers converged again, when we started working on kernel physics.”

Penny said, “It all came from that day we were on Mercury with Dad, we were eleven years old, when the first hulk ship was launched. That was what inspired us to go into kernel research in the first place.”

Stef closed her eyes, just for a moment. No. I was there alone. With Dad. You weren’t there, not even as some unwelcome ghost. That was my day, not yours…

“And then it was all fine until we went into the Hatch on Mercury,” Penny said sadly. “I went through first, Stef. You followed me in. And when I went into that second chamber, and I turned around and you saw me, I could see you didn’t recognise me. We’d only been out of each other’s sight for a minute—”

“Less than that,” Earthshine said. “I have studied the record. Thirty-eight seconds.”

“And my memory is different,” Stef said. “I went alone into the Hatch. I opened the second hatch. There was Penny, already in the next chamber.”

“Before that time, you, Stef, clearly knew your sister. Afterwards you were baffled by her very existence, though you did your best to conceal it when you realised that something was very wrong.”

Stef felt resentment flare. “You’re not allowed access to any material on kernel physics. That’s a UN law.”

“Of course,” Earthshine said smoothly. “But any such law needs a defined boundary. And I, or my legal advisers, push assiduously at that boundary. Wouldn’t you? I am entitled to explore the implications of kernel science, even if I must turn my head away from the physics itself. A visual record of events at the Hatch tells me little about the underlying physics, and much of it is in the public domain anyhow.” He leaned forward. “Major Kalinski—I mean, Stef. Only you remember how it was before. Your life as an only child. Yes? Most people therefore assume your memory is faulty.”

Stef said, “Or that exposure to the Hatch messed with my mind and sent me mildly crazy.”

He shook his head. “But that’s not what you believe, is it, Major? Now consider the alternative. If your mind hasn’t been tampered with—if your memories are authentic—”

“This makes no sense,” Penny said, growing hostile.

Earthshine urged, “Just run with this for a moment. Stef, what’s your alternative hypothesis?”

She took a deep breath. “History changed. What else? The minute I opened that Hatch.”

Earthshine nodded. “Before, there was a different history.”

“Where I was an only child. Where I had a different name, for God’s sake. I was Stephanie Penelope Kalinski, not Stephanie Karen, and Penelope Dianne never existed. And when I opened that Hatch and stepped inside, there you were, Penny—real, live, impossible. With a set of memories of a different past. Memories that were in everybody else’s head too.”

“All except yours,” Earthshine said. “Just suppose you’re right, Stef. Just suppose reality was changed, that the Hatch, on accepting you, immediately tinkered with the past—at least with your own past. Giving you a sister you never had. And presumably causing subsequent small changes that rippled away from that big central adjustment.”

Penny was clearly uncomfortable, and Stef was sure she knew why. They were talking about a world where she’d never even been born, and that must be existentially terrifying. Penny said now, “Occam’s razor. Basic principle of science. The idea that Stef somehow got a kind of amnesia is a lot simpler than the idea that the whole universe has been changed to generate a new reality.”

“Well, Occam has been dead a long time,” Earthshine said mildly. “And is the alternative really so preposterous? We know that the Hatch technology involves some kind of manipulation of space-time. You both clambered down into a hole beneath the Hatch that could not exist, according to the geophysics measurements. What is a history change but another such manipulation? In time, rather than space. Stef, I suspect you may not have gone much further with this line of thinking yourself, even in the privacy of your own head.”

“What are you getting at?”

“I mean that if there has been some kind of history change, effected by the Hatch, or whoever built the Hatch—”

Penny snorted. “Oh, this is—”

“Then it’s been kind of a messy change, hasn’t it? I mean, it hasn’t been clean. We know that it’s left at least one trace of what went before, in your own memory, Stef.”

“That’s hardly evidence,” Penny snapped.

“It is to Stef. Maybe it had something to do with you being inside the Hatch itself, at the moment the change was effected—”

“And what would be the point?” Penny demanded now. “You’re talking about changing history. If you can do that, why not, hell, wipe out a climate Jolt or two? Or even wipe out the warming altogether—why not go back and shoot Henry Ford?”

Stef said, her mind racing, “Maybe it—or they, the Hatch-makers, whoever is behind this—couldn’t manage anything on that scale. Maybe they didn’t know enough about us, about humanity, to make more than the smallest change. Maybe this was all they could manage. For now, anyhow.” She looked at Earthshine. “But why us? I mean, why me? What’s significant about me, or my life?”

“Everything, “ Earthshine said. “Or nothing. Maybe it was just the fact that you were first into the Hatch. This was a kind of—test run. An exploration. But if so, as I said—”

“The execution was sloppy,” Stef said. “With one loose end left, in my memory. Trant and King remembered Penny opening the second hatchway and going through ahead of me. I remember opening the second hatch myself, then seeing Penny for the first time… Sloppy.”

“At least one loose end.”

Stef looked at him sharply.

Penny stood. “What do you mean? Have you found another ‘loose end’? Have you got some kind of proof?”

He smiled as she loomed over him. “Well, wasn’t it logical to at least look? If there is one ragged corner there could easily be more. So I looked. And—”

Stef said, “Is that why you brought us to France? Is there something you want to show us?”

“I can do this virtually,” he said. “Or it may be better if you travel physically and see for yourselves, with your own eyes.”

“Later,” they both said, their identical voices double-tracking.

“Just show us,” Stef said. “Please.”

Penny sat down, looking frankly scared.

Earthshine nodded, waved a hand, and the room dissolved.

Chapter 43

A footprint.

Yuri froze.

Beside him, Mardina pulled Beth close.

A human footprint, in the mud. Clear as day. Yuri could see the ball of the foot, the heel. He could count the toes.

“Where there’s one print,” Mardina murmured, “there are going to be others. Look, Yuri. That way…” She pointed west across the arid country away from the lake.

The trail of prints was clearly visible, like shallow craters in the crusty ground, one after another, left, right. Off to the horizon.

“Let’s get back to the ColU,” Yuri said.

“Right.”

As they headed, half-running, back around the lake, Beth’s excitement turned to alarm. “What is it? Have I done something wrong?”

“No, sweetie,” Mardina said. “Not at all.”

“Is it that footprint? Is it somebody bad?”

“No, no, nothing like that,” Yuri said. He murmured to Mardina, “We’re scaring her.”

“She’s a right to be scared.”

“This shouldn’t be possible, should it? The Ad Astra drops were supposed to be too far apart.”

“Yet it’s happened.”

They got back to their new campsite, still little more than a heap of supplies, the logs and beams and panels of their dismantled house, a mound of carefully manufactured terrestrial topsoil, other junk. Yuri rummaged until he found a crossbow and bolts. He already had his hunting knife tucked into his belt. “I’ll go and check it out. You look after Beth.”

Mardina curled her lip. “Go ahead, hero.”

Yuri picked up their one flare pistol, it still had a few cartridges left, and stuffed it into his tunic pocket. “Well, if I fire this, come and save me.”

“I’ll save you, Daddy.”

“Thank you, sweetie.” He kissed the top of Beth’s head, grinned at Mardina with a confidence he didn’t feel, and set off.

He tracked back the way they had come. There was the first footprint, bright and sharp. Completely ignored by the builders nearby.

Without hesitating, he went further, following the track of prints across the dry country, heading steadily west, jogging, the crossbow in his hand. In the years since the stranding, Mardina had insisted they both practised with the crossbow until they were reasonably expert. Yuri hadn’t disagreed. There was nothing to shoot at round here, but you never knew. Now it looked as if that might pay off.

More humans! There had been times, especially before Beth had come along, when he had longed for other people to show up, somehow, somewhere—even his enemies, even arsehole Peacekeepers, even that smug bastard astronaut McGregor. He still felt that way sometimes. But now it was different; now he had Beth to shelter and protect. If there were other survivors of the drops down here, who knew what state they would be in? Who knew how they would react to him?

He had come to think of Per Ardua as his, he realised. His and his family’s. It made no sense, but there you were. Now he resented having to share it.

And he feared for his family. He had a mental image of the jilla builders’ efficient genocide: the imprisoning, the wordless, relentless butchery.

He stopped. Straight ahead of him now was a sandstone bluff, low, eroded, sticking out of the ground, a typical Arduan feature. And beside it, a figure, a single human being. He, she, was crouched by the bluff, digging into the ground with one hand—no, drinking, he saw, there must be a spring there, a pool.

He walked steadily forward. He held the crossbow at his side, loosely, his finger away from the trigger. He didn’t call out.

Soon enough the figure by the rock bluff spotted him. A slim woman, she stood up straight. She wore no shoes, trousers that were the cut-down remains of an orange jumpsuit, a black shirt that looked like half an astronaut’s uniform, and a homemade coolie hat made of stem bark, not unlike his own. She had lost one arm, amputated above the elbow, he saw, shocked. The tattoos on her face were solid black slabs, and seemed designed to emphasise the glare of her pale blue eyes.

He knew her. She was Delga, who he’d known on the ship, and on Mars before that. The snow queen of Eden.

Delga grinned at him. “Hello, ice boy.”

Chapter 44

Having met, they had to decide to go one way or the other. Yuri chose to walk west with Delga, towards her group, which she called “the mothers”, rather than back towards Mardina.

“Only a few klicks,” she said.

“Yeah. We’re further away than that.” That was a lie; in fact Mardina and Beth were a lot closer. His instinct was to obscure, to hide, to protect. Of course she might know all about his little group already.

Delga had aged, and life on Per Ardua had evidently toughened her; she looked scrawnier, more wrinkled, but strong, leathery. Her tattoos hadn’t faded, her face was just as blade-like, just as threatening. Despite the loss of that arm he was quite sure she’d have weapons available. As, indeed, he had.

He was trying to work through the shock. Just encountering another human being, any other human, here on this static world, changed everything. And now it turned out to be Delga.

Delga’s face was a tattooed mask, under a scalp shaven in elaborate whorls. Yuri barely knew her. He’d only come across her a couple of times on Mars. On the Ad Astra she’d been in the same hulk as him, but again he’d kept his distance. He’d wanted nothing to do with her products, her chain of contacts, her suppliers and users. The last time he’d seen her, he remembered now, she was leading a bunch of rebels up towards the ship’s bridge, after the arrival at Proxima. She was the type to have survived, he supposed.

He said now, “So what were you doing all the way out here?”

“Stretching my legs. What do you think? The one thing this place does have is room, room to walk off until you’re over the horizon and alone. Can’t do that in a Martian hovel, right? Or in some hulk of a ship. Or on most of Earth these days, probably.” She jerked a thumb over her shoulder. “I come out this way for the water. The springs. And there’s a hollow a little further out that way, more springs, but it just got flooded.”

She must mean the hollow that now held the jilla lake.

She looked at him, shrewd, analytical. “You don’t know this area well.”

“No. We’re on the move.”

She picked that apart. “We. Who, how many? How heavily armed? On the move. From where, to where?” She grinned. “Don’t worry. We’ll be sharing soon enough. You know, ice boy, of everybody in that dumb hulk I never picked you out as one of the survivors, here in the Bowl.”

The Bowl? The air ahead was misty; as they walked he thought he smelled water, but his view was blocked by a low rise, worn hills. “Why not me?”

“Because, back in Eden, you came out of that cryo tank like you’d been dropped from the sky. You never fitted in, even on Mars. You didn’t make any contacts, you didn’t have any networks. You didn’t even have a way to pay off the Peacekeepers. We noticed you, though. The ice boy, right? Your name is Yuri. What the hell kind of a name is that?”

“Not my name.”

“Then why are you called it?”

“Some joker called me that when they woke me up, on Mars. It’s the name of an astronaut. Or a cosmonaut. The first one, I think.”

She shrugged. “Never heard of him. So what’s your real name?”

He looked away.

“You’ve put aside your lousy past, is that it? What kind of accent is that, by the way, Aussie?”

“North British. I grew up in Manchester, at the border with Angleterre, the Euro province.”

“You sound Australian to me.”

“You all sound sort of Hispanic to me.”

“How long were you frozen, a hundred years?”

“Nearer eighty.”

“Were you one of the Heroic Generation? What did it feel like to be a Waster?”

“We weren’t called those names then. I was too young anyhow.”

She grunted. “Surprised they didn’t call you as a witness in the trials. But you escaped it all, didn’t you? You in your freezer tray.”

He was reluctant to answer, but it was hard to turn away from her iron gaze. The whole conversation, suddenly thrust upon him, was bizarre, like his deepest past suddenly pushing up out of the Arduan ground. “It wasn’t my choice. It was an experiment. There were too many of us, my generation. So they tried freezing us in these big honeycomb banks, under the ground, in Antarctica. We’d have less of a footprint that way.”

“Your parents got rid of you. That’s what happened. Whereas now they get rid of us from Earth to Mars. Or even further, right? I suppose it was cheaper to ship you out to Mars still frozen than to deal with you any other way. Well, on behalf of the future, I hope you enjoyed your stay on Mars, my friend. The butthole of the solar system.”

He glared at her, defiant. “If it’s so bad, why were you there?”

She shrugged. “We were there, the UN was there, because the Chinese were there. We can’t let them have Mars all to themselves, can we? And the UN has these big ships now, the hulks, big powerful engines. Nothing like the steam-engine put-puts they had in your day, I bet. Now they can afford to send people to Mars who don’t even want to go. Even to the stars! That’s progress for you.” She laughed and spat. “Funny thing, life. You never know what it’s going to throw at you next.”

He didn’t like her dismissive tone. “So how did you survive here?”

“See for yourself.”

They rounded the low hills, the view opened up, and Yuri saw a river, a ribbon of blue-black water flowing across the flat, arid landscape. It was an astonishing sight, after all these years stuck by the jilla lake. The bank was lined by the usual beds of stems in their marshes, but he saw no signs of builders or their works, at this first glance.

And there were people here. People and their stuff. Some kind of tepees, frames hung with cloth, smoke from fires rising reluctantly in the still air. What looked like a cut-down ColU, without the dome and manipulator arms. And the people: women and kids gathered around a hearth, a handful of men further away, clustered around another, smaller fire. Like Delga, they all wore what looked like cut-up ship’s-issue clothing, even the little kids. Yuri recognised none of the adults, at first glance.

When Yuri was spotted with Delga, some of the women got to their feet and reached for weapons. Yuri could see ISF-issue crossbows, what looked like home-made spears. Delga held up her good arm in a signifier that it was OK, Yuri was no threat. But the women watched and waited, intent. The men by their fire didn’t bother to rise; they just looked on apathetically.

They walked forward, Yuri wary.

“Look north,” Delga said. “That patch of green? Potatoes, our latest crop. Ready for harvesting soon and we’ll be out of here. And, further north, see?”

He saw more smoke, a dirty scar on the landscape, figures moving, dimly visible, another couple of ColUs perhaps. “More people?”

“Yep. Our difficult neighbours. Klein.”

“Gustave Klein? From the hulk? The big man?”

“He survived. Well, you’d expect him to. We deal with him. No choice, Yuri. Planet’s big, but humanity’s small here.”

They were approaching the central group now, the women, the big fire. He counted quickly: six women together, a bunch of kids, five men in the other group. The women were being cautious of him, he saw, some of them shepherding the children out of the way, others drawing up in a loose line with their weapons. They were all tattooed, more or less as Delga was—even the older children, some of whom looked as old as ten years maybe, presumably conceived not long after the landings. Yuri made sure he kept his hands open and visible.

Delga noticed this. “I’m not going to tell them you’re no threat. For one thing I’m not a leader here, and they wouldn’t listen to me. Well, we don’t have a leader, haven’t felt we needed one since we put down Hugo Judd. For another I don’t trust you. I mean, you’re obviously lying, right? About your people, where they are. You’re not a good liar, ice boy. Maybe your facial muscles never thawed out from that cryo tank.”

“Yuri?” One of the armed women broke from the line, and walked forward cautiously.

“Anna, right? Anna Vigil.” He barely recognised her under the tattoo on her face, behind the spear she wielded easily, as if she’d done a lot of practice. Yet he was relieved to see her.

“God, after all these years—I just assumed you were dead. For sure I never thought I’d see you again. Cole!” She glanced over her shoulder. “Cole, come here…” One of the children came forward reluctantly, a boy, skinny, wide-eyed, maybe fourteen years old, but already taller than his mother. “You’ll remember Cole from the ship.”

The boy stared suspiciously. Yuri realised how rare it must be for kids like this to meet strangers, how wary they must be. He and Mardina would have to manage Beth through this process, when the time came.

The boy soon backed away and ran off to join the other kids, who were engaged in some game of running and capturing that must have been broken off when Yuri came wandering in from the plain; now the game was proving more interesting than the stranger, and they returned to it. A couple of them, meanwhile, were throwing stones at a group of builders by the riverbank. Yuri guessed this group hadn’t taken the time to watch the builders that he had. The builders swivelled and scuttled to get away.

Anna said, “You and that buddy of yours, you used to help me—Lemmy?”

“Lemmy Pink.”

“Did he land with you?”

“Yes.” He shrugged. “He didn’t make it.”

She nodded, as if she was used to news like that. “It’s OK,” Anna said now to the group. “I know this guy. He used to help me out on the ship. Got me supplies for the baby.”

The rest of the women, none of whom Yuri recognised, backed off, lowering their weapons, but they kept their eyes on him. The other group, the oddly excluded men around their own fire, huddled and muttered, glancing over at him.

“This way, ice boy.” Delga led Yuri towards the women’s fire. They had seats set out here in the open air, some of them remnants of ship’s supplies, others improvised from storage drums and crates. All the equipment here, the tents, the furniture and tools, looked mobile to Yuri, easily packed up. They were a people used to moving, as indeed he and Mardina and Beth had become.

“Sit,” snapped Delga. “Talk. Keep your hands where we can see them.”

Yuri obeyed. Anna, smiling, sat on one side of him, Delga on the other.

One of the other women, weaponless, approached Yuri. “Yuri, right? My name’s Dorothy Wynn. I’m on hearth duty today. You want something to eat, some tea?” Aged about forty, her greying blonde hair pulled back from a handsome face tattooed like the rest, she had what Yuri, in his own time, would have labelled a brisk US east coast accent.

“Tea?”

She filled a metal mug from a pan on the fire. “Brewed from nettles, Earth nettles I mean. They grow fast here, in compost. Surprisingly useful.”

“Our ColU didn’t bring along any nettles. I mean—”

She shrugged and sat down. “They seem to have had variant programming. I guess they were trying out different possibilities, the mission designers, to see what worked and what didn’t.”

Delga grinned blackly. “And see who died and who didn’t.”

Dorothy Wynn said, “Yuri, Delga is one of our more morbid personalities.”

Delga said, mimicking her badly, “While Dorothy is one of our more sane personalities. Or she thinks she is. Surprising you ended up down in the Bowl with the rest of us, in that case, isn’t it?”

Wynn seemed unfazed. “Oh, ignore her. Yuri, I was a corporate accountant, working for one of the big reclamation companies in New New York. My first crime was to siphon off a little of my employer’s wealth for—well, let’s call it an indulgence. My second crime was to get caught. Unforgivably clumsy. And so I ended up here. You know, Yuri, I never expected to meet you. But I remember the chatter about you on the Ad Astra. The man from the past. How fascinating. More tea?”

“No, I’m fine.” Yuri, stuck alone with Mardina for all these years, felt bewildered, almost shy. He was unused to this kind of complicated interplay between personalities. And he became aware of scrutiny from the men, sitting a way apart. One of them was muttering, staring, pointing. “Fantôme… il est un fantôme…”

“What’s he saying?”

“That you’re a ghost,” Anna said. “His name’s Roland. French Canadian, and he reverts to French when he gets scared.”

“Why a ghost? You have met other groups before, right? Like Klein’s over there.”

“Yes,” Delga said. “But you just came wandering out of nowhere, alone, ice boy. Look at what you’re wearing.” She fingered his leggings, his tunic of woven stem bark. “Like you’ve risen up out of the Bowl dirt.”

“There are stories about ghosts,” Anna said. “Well, one ghost. Of Dexter Cole, you know? The first pioneer who came out here alone…”

“Who you named your kid for.”

“They say he haunts this world. Maybe he lives on, in the unending night of the far side. That kind of thing.”

Strange, Yuri thought, that his own group had come up with much the same story.

Dorothy snorted. “What a crock. If you ask me Gustave Klein just made it all up to keep his boys in check.”

Yuri looked around at their faces: Anna puzzled but friendly, Delga cynical, Dorothy competent but cautious, the French guy Roland wide-eyed.

Anna asked, “Yuri? Are you OK?”

“To be honest I’m feeling kind of bewildered. Turned around.”

“Maybe we should put him with the men,” Dorothy said, and they all laughed.

Anna patted his arm. “Look, Yuri. We had some trouble. We were dropped down here, just as you were, I guess. The shuttle landed some way to the north. And after it took off again, after all those speeches by the astronauts —”

“What kind of trouble?”

“With the men,” Dorothy said with some disgust. “Some of them tried to take charge. Others tried to lay claim to us.” She eyed him. “I’m betting it was the same with your group.”

“It got a bit rough,” he admitted neutrally.

“We had to put one of them down,” Dorothy said. “Two more killed each other, but one of us got caught in the crossfire, so to speak. And so—here we are, the survivors.”

Delga was watching Yuri’s reaction. “What are you making of all this, ice boy? Us and them. We make the decisions here, the women. The men—well, we need them to make babies. Other than that they do what we tell them.”

Dorothy laughed. “That’s pretty much true. Yuri, you might know something about this—I think we’ve got a social structure here like the elephants in the wild. Those old animals, you know? I once took a virtual safari, a corporate team-building thing. I remember the guide saying how a core of females used to be at the heart of elephant society. And the males formed bachelor herds, where they fought the whole time, competing for a chance to mate. In the same way, the men are on the periphery, really.”

Yuri shrugged, irritated. He thought he’d left all this stuff behind, years ago, people making dumb guesses about the age he’d come from. “The only elephant I ever saw was a gen-enged resurrected mammoth in a zoo.”

Delga was watching him, having fun in her manipulative, intrusive way, he realised. “Poor little mammoth, eh? Just like you, out of his time. Poor little ice boy.”

The children broke out of their circle of play and ran, laughing, down to the river. The water was flowing north, Yuri noticed now, away from the substellar zone to the south, towards the terminator to the north.

“So you had kids,” he said. “Just as Major McGregor ordered you to.”

Delga laughed. “You mean, all that Heinrich Himmler Adam-and-Eve crap? We didn’t take any notice of that bullshit. We just had kids. Even me, Earthman. See if you can spot my little Freddie. We keep our men like stud bulls. Want to join them, Yuri? Your last-century genes would enrich the pool—”

“Leave him alone,” Anna snapped. “It’s not like that, Yuri, she’s exaggerating.”

“Your camp—you’re pretty mobile, right?”

Dorothy said, “Well, we stick around long enough to raise a crop of potatoes, grow a field of grass. Raw material for the iron cows—it must be the same for you. Maybe a year in each place. But then, yes, we move on.”

“We’re following the river south,” Anna said. “Upstream.”

“Why that way?”

Dorothy said, “We like the idea of maybe reaching the source one day.”

“Maybe that will be at the substellar,” Delga said. “You remember that place, the storm system, the clump of forest, we all saw it from orbit? The navel of this world. What’s there, do you think?”

That had never occurred to Yuri, the significance of the substellar point. Maybe because he had never imagined he’d find a way to reach it.

“But it’s not just that,” Anna said. “We need to head south anyhow. Seems to some of us that the weather’s getting colder, bit by bit. You must have noticed the sunspot swarms on Proxima.”

“Yeah. And then there’s the volcanism.”

Dorothy frowned. “What volcanism?”

“To the north of here.” He meant the slow uplift that seemed to have triggered the builders to move the jilla lake.

She pressed, “How do you know about that?”

Delga asked, “Is that why you’re on the move, Yuri? You and your people?”

He said nothing.

Anna touched his arm again, a surprisingly gentle, friendly gesture. “Leave him alone. We went through it all with Klein, remember, when we met him and his gang of thugs. Let Yuri tell us whatever he wants, in his own time.”

He asked now, “How did you find the river? We were dumped in the middle of a dry landscape, almost a desert, at a sort of oasis.”

Delga snapped, “If that’s so how did you get out?”

“Hush,” Anna said. “Yuri, it was hard. A trek. But we knew which way to go. We had a map.”

“A map?”

“A map of this whole quadrant of the planet,” Dorothy said. “I’ll show you.” She stood, and ducked into one of the tents.

Yuri said sheepishly, “We have a map too. Kind of. I always carry it.” He produced Lemmy’s battered map from his pocket, unfolded it. “It doesn’t look much, but Lemmy Pink took weeks over this after the astronauts left…”

Dorothy returned with a map of her own, a single piece of paper. She folded it out on the ground by Yuri’s. Dorothy’s map covered just the north-east quadrant of the starlit face of Per Ardua—or “the Bowl”—but it was a professional piece of work, properly printed, showing coastlines, seas, rivers, mountain ranges, the features even assigned tentative names. And there were little shuttle symbols, scattered across the quadrant, which Yuri guessed signified landing sites. He looked up at Dorothy. “Where did you get this?”

“I bribed an astronaut. Oh, not with sex, the usual currency. I used to move in influential circles, back home. I happened to know something about this woman’s family which she did not want revealed to her colleagues… With this we could tell how close we were to the river. It was tough, but we made a dash for it when the children were still small.”

Delga stared at the two maps. “Look. This long scribble of the rat boy’s just has to be our river. Which does go all the way to the substellar point. Wow.”

“We may never get that far,” Dorothy said. “It’s a hell of a long way. Especially if we have to stop to grow a crop of potatoes every fifty klicks. And isn’t the climate there supposed to be difficult? Too hot—”

“If the whole world is getting cold,” Anna said reasonably, “then that might solve the problem.”

“And besides,” Delga said, “where the hell else is there to go?” She faced Yuri. “So what about it, Earthman? You going to join us?”

He couldn’t see a choice. There would be better protection in a larger group, a better chance of survival. And at least with this group there would be other kids for Beth to meet—a choice, at least, of partners for life. Maybe even more in Klein’s group, and he glanced that way.

Delga noticed the look. “Yeah. You’re going to have to go face the big man.”

“But bring your people here first,” Anna said. “Maybe you ought to go and tell them they aren’t alone any more.”

Yuri stood, and thanked them for their hospitality. He felt like his manners were rusty. Then he set out alone for the jilla lake and home, wondering how he was going to break all this to Mardina and Beth.

Chapter 45

When they came back to the camp by the river, it was as a convoy: Yuri and Mardina walked, and Beth rode on the hood of the ColU.

They had let Beth pick out her own favourite clothes, which were all colourful cut-downs from the old ISF gear. And she packed a bag with gifts for the children, from old toys to choice potatoes from the latest crop, and pretty rocks she’d found over the years. Though whether she had a clear idea of what “children” were going to be like, Yuri had no idea. She might imagine some version of the builders, Mister Sticks grown large and wearing human clothes.

Yuri had suggested to Mardina that they wear what was left of their own ISF-issue gear, in order to blend in with the crowd a little better. But Mardina went to the opposite extreme, picking out her drabbest stem-case work clothes, her coolie hat, even her bark sandals. “This is who I am now,” she said evenly.

Not for the first time in his life, Yuri couldn’t read her mood. But he went along with her decision.

The whole of Delga’s camp turned out to watch them approach, the men and women in their little huddles, the kids behind the women.

“Not exactly welcoming,” Mardina murmured.

“At least they’re not waving crossbows this time.”

Beth just stared at the children, stared and stared. And the ColU swivelled its camera mounts to inspect the mutilated machine that stood patiently at the edge of this colony’s potato field.

They got to within about ten metres. Then one of the women stepped forward, staring at Mardina. “I know you. She’s a fucking astronaut!”

Mardina murmured to Yuri, “I take it you didn’t explain my particular circumstances.”

“I didn’t tell them anything.”

“Fair enough—”

“An astronaut! I always hated you bastards, even before I got on the ship. Jones, that was your name.”

“It still is.”

“Why, you mouthy—” And the woman launched herself out of the group and went straight for Mardina, running flat out, her hands outstretched as if to grab Mardina’s throat.

Mardina stepped aside, stuck out a leg and sent the woman sprawling. “Ten years out of the service but my ISF training’s still there. Good to know.” The woman was up on her knees, spitting dirt out of her mouth. “Now, one quick chop to the neck—”

Yuri held Mardina’s arm. “Leave her to the others.”

Some of the women, and one man, came running up. They hauled the woman to her feet, her arms firmly held. “For God’s sake, Frieda, we have to live with these people…”

Dorothy Wynn stepped forward to apologise. Delga just laughed.

They were brought into the camp reasonably peacefully. Yuri and Mardina sat by the women’s fire and were offered more nettle tea. The men of the colony hung back, evidently curious. The ColU rolled away to inspect its silent brother by the potato field.

Beth stared at Delga’s stump of an arm. And then, wide-eyed with astonishment, she was cautiously welcomed by the children.

“Play nice, Freddie,” Delga called with a hint of venom. “So, ice boy. Full of surprises, aren’t you? Only two of you. Two survivors, of fourteen.”

“It’s a long story,” Yuri said.

“And not all that dissimilar to yours, I’ll bet,” Mardina said levelly, pointedly looking around at the group, the eleven adults.

“More extreme though,” Delga said. “We’re all survivors, I guess, here in the Bowl. But you two evidently pushed it to the limit. Respect.”

Dorothy Wynn said, “I’m sorry how Frieda took a pop at you like that.”

Mardina shrugged. “She’s right. I am ISF crew, or was.”

“But I’m guessing you didn’t volunteer to stay down here.”

“I filled a gap in the manifest. The drop group was short… I had the right genetic diversity. Lucky me.”

“We’re all here now,” Dorothy said firmly. “Which is all that matters.”

Anna said, “And you had a kid, even though it was just the two of you? That took some guts.”

Yuri and Mardina shared an awkward glance. This was very private stuff, but these others had been in a similar position. Yuri said at length, “I think we concluded that it took less guts than not having a kid.”

“And another? Did you think about having more?”

This time neither of them was willing to answer. Even after Beth was born they’d found such issues difficult to discuss. Their whole world was focused on one person, on Beth; somehow they hadn’t been able to imagine breaking that up with a second child. Maybe someday they would have got around to it, the alternative being to let Beth grow old and die alone. But that, Yuri realised slowly, was the old game, under the old rules. Looking around at these people, he saw that everything was different now—for Beth too.

Still they weren’t answering Anna’s question, and the silence stretched. Yuri was relieved when another familiar figure walked over to break things up.

“Hey, Yuri. I thought you were dead, man…”

It was Liu Tao. Yuri could see that his old comrade from the ship had come from the Klein camp, to the north. He wore the remains of an ISF-issue coverall, with two bands of red ribbon around his right biceps.

Yuri stood up. They shook hands, embraced briefly. Yuri was unreasonably glad to see Liu. “Never thought I’d see you again. I always thought you’d come through, though.”

Liu shrugged. “Well, I lived through a spaceship crash on Mars and two years in a UN jail before I was shoved aboard the Ad Astra. So I’m a tough guy, right?”

“How touching,” Delga said. “Male bonding. We don’t get enough male bonding around here, do we, Dorothy?”

“Delga…”

Mardina said, “Klein sent you over. Right, Liu? One of his right-hand men now, are you? Hence the pretty ribbons on your arm.”

Liu shrugged. “Yeah. Something like that. He’s inviting you over for a drink, Yuri. You and Lieutenant Jones here.”

“A drink?”

“Potato vodka. Not bad, at least the stuff Gustave drinks.”

“And that’s not really an invitation, Yuri,” Delga said, smiling cruelly. “It’s an order.”

Mardina said, “I think we’re through taking orders from anybody.”

Yuri looked across at the Klein camp, and he glanced around at Dorothy, Delga, the others; he didn’t know what kind of accommodation this group had come to with Klein. “Just this once,” he murmured to Mardina. “Let him get his own way just this once. Hear what he has to say. Then we’ll figure out our own policy. All right?”

She shrugged, and got to her feet.

Anna said, “You can leave Beth here. She’s fine.”

And so she was, Yuri could see; she was running around with the other kids in some complicated tag game as if she’d grown up with it.

But Mardina picked up Beth’s bag and slung it over her shoulder. “Maybe Beth left some old toys we can give to Klein and his henchmen.”

The others laughed, but Yuri could see Mardina’s smile was forced. He glared at her. What are you up to? She looked away, making no reply, wordless or otherwise.

It was just a short walk downstream to Klein’s camp, with the way led by Liu Tao. Dorothy and Delga walked with them too. The ColU rolled alongside Yuri and Mardina, saying it wanted to inspect the machines in the Klein camp, as it had Delga’s.

The camp was superficially like Delga’s, with tents and lean-tos of the local timber evidently designed for breaking down and rebuilding. A number of fires burned. At first glance Yuri counted twenty adults here, more than one shuttle-load. There were men, women, and children, but gathered in little family groups, Yuri thought, rather than in the split-sex communal arrangements of Delga’s group.

People stared as they came through. They seemed to flinch away, fearfully, and parents kept their kids out of the way. Some of the men wore arm ribbons, like Liu’s—none of the women. And Yuri noticed injuries, burns or scars, on arms and faces. Even some of the children had been injured.

The biggest difference of all was at the heart of the camp. There was one substantial house, like a cabin with vertical walls and a pitched roof, that must have taken a lot of effort to rebuild when it was moved. And alongside the house was another ColU, or the remains of one, its dome detached, its manipulator arms lost. On top of this was set a chair, of carved wood and cushions.

And on the chair sat Gustave Klein, appearing as corpulent as ever. He wore what looked like an astronaut uniform, let out to fit his frame, black and sleek, with six of those arm ribbons wrapped around his fat biceps. He smiled down at Yuri. His head shaved, his face round, multiple chins tucked down on his chest; it was like looking up at the moon of Earth. “I don’t even remember you,” Klein said.

“Thanks.”

“But I remember you. The delectable Lieutenant Mardina Jones.” He leaned forward and sniffed. “Oh, we all had the hots for you, back in the day.”

“And I remember you, Klein, and you’re as disgusting now as you were then.”

He roared laughter. “Feisty, isn’t she? Well, you’re not in command any more, for all your arrogance.” He glared at the ColU. “You. What are you looking at?”

“At the autonomous colonisation unit on which you sit.” The ColU’s cameras pivoted to look at the group’s second unit, which stood at the edge of another potato field. That too had had its dome removed, all its sensors, though its manipulator arms remained. “You acquired a second machine.”

“ ‘Acquired’. Yeah. Good word, that. When we came across another group and we ‘acquired’ them and all their gear. Mostly we acquired the women, of course,” and he cackled laughter, leering at Mardina.

“And what of the units’ AI modules?” the ColU asked.

“Well, we cut them out and dumped them,” Klein said. “When they wouldn’t do what we wanted.”

“We did the same,” Dorothy admitted. “Didn’t you ever think of that?”

“Evidently not,” said Mardina evenly.

“You dumped them,” the ColU said. “Fully sentient, rendered as if limbless and sightless, dumped them in the sand and abandoned them. Unable even to die—”

Mardina said, “I think there have been greater cruelties committed on this planet than that, ColU.”

The ColU rolled away. “I will inspect that machine. And I will make it a personal goal,” it said, receding, “to recover all my lost and wounded brothers. Some day, somehow…”

Klein ignored it. He stared at Yuri, curiously. “Just the two of you, right? We all got dropped in the middle of nowhere. How did you get out?”

“Tell us how you got out.”

Liu answered for him. “It was kind of brutal,” he admitted. “Turns out we were left even further from any other water sources than most of the shuttle groups we’ve heard about.”

“I wonder why,” Mardina said, staring up at Klein.

“China boy’s too squeamish to tell you how it was,” Klein said. “We didn’t have enough water from the start. Then the lake we were stuck by started drying out. Even the little reedy natives cleared off. Some astronaut screwed up, we should never have been dropped there. So we walked out. And you know how we survived?” He licked his lips, staring back at her. “You want to know what your precious ISF astronauts, your marvellous Major McGregor, made us do? We drank the blood of those who weren’t going to make it. That’s how we survived. Quite a story, huh? A story that will be told as long as there are people on Kleinworld. And don’t pretend you’re somehow above all that, China boy. You stained your mouth too.”

Liu looked away.

Mardina said, “Kleinworld? You’ve got to be kidding.”

Delga grinned. “We just call it the Bowl. Because that’s how it feels, doesn’t it? When you look up at that big sun in the sky, never moving. Like you’re stuck at the bottom of a great big bowl, with slippery sides that you can never climb out of.”

“We call it Per Ardua,” Yuri said, and he explained why.

Dorothy Wynn nodded. “I rather like that.”

“ ‘I rather like that’,” Klein snapped mockingly. “Oh, do you? Well, I fucking don’t. Typical smartass stuff from you astronauts—right, Lieutenant Jones? Let me tell you something. You’re a long way from the officers’ lounge now. You’re in my world, whether you call it that or not. I’m the power here. Look around. And I’ll tell you what you’re going to do before—”

With a single smooth movement Mardina pulled a crossbow out of Beth’s bag, raised it, and shot him in the eye. He fell back on his big chair, limbs splayed, mouth open, and was still.

For a moment there was silence, save for the gurgling of Klein’s gut as it shut down. Nobody moved. Then Mardina held up the crossbow, loaded it again, and showed it to Klein’s “officers”.

Delga was the first to react. She laughed. “Wow. How did you—”

“Practice,” Yuri said grimly.

“Practice, yes,” Mardina said. “I’ve had a lot of time for that the last ten years. But I haven’t got time for an asshole like Klein. And I’ve got a daughter to protect. So, that’s that dealt with. Anybody got any objections? No? Good. Let’s get out of here; we’ve got a lot to talk about. By the way—” she looked contemptuously at Liu’s arms, the ribbons, “—you won’t be needing those any more.”

Flanked by Dorothy and Delga, she walked out of the camp, heading upstream.

Yuri and Liu fell in behind her. Yuri was ready for trouble, but Klein’s people seemed stunned. None of them had even gone to the body yet.

“You’ve got a tiger by the tail there, my friend,” Liu murmured to Yuri.

“Tell me about it.”

As they walked back to Delga’s camp, a few flakes of snow started falling from the sky. By the time they got back Beth and the other children were dancing and shouting, excited by the thickening fall.

Chapter 46

The walls, the carpet melted back, to reveal a washed-out blue sky, well-watered grass underfoot. Only their three chairs remained, and Stef wondered how much else of Earthshine’s fancy chamber had been a simulation.

Earthshine remained seated, while Stef and Penny stood and looked around. They were in a graveyard, set in the grounds of a small country church, evidently very old. The graves in their rows were topped by weathered stones, and some by more modern virtual memorials, nodding flowers or dancing figures or scraps of wedding albums or baby photos, sustained by the energies of the generous sunlight.

“We’re not far from Paris,” Earthshine said. “I mean, that’s where the source of this projection is. Once you would have seen the city smog as a smear in the sky, off to the north. Long gone now. The simulation is based on a live feed, incidentally.”

“I recognise this place,” Penny said. “We came here when Dad was buried.”

“I came here alone,” Stef said.

“Whatever. He wanted to be buried beside Mom.”

Earthshine said, “Who in turn was buried beside her own mother. Your grandmother was a Parisian, and so here we are… I am drawn to graveyards, you know. Fascinating, poignant places. The evidence of human mortality, which I do not share—”

“Even though you were once human,” Penny said.

That surprised Stef. “What are you talking about?”

Penny smiled ruefully. “Since we got this summons, while you have been researching me, I’ve been researching our host…”

It was another outcome of the Heroic Generation age, she said. “Earthshine is actually the youngest of the Core AIs. Already his brothers were strong. They were useful for supporting the big post-Jolt projects: global in scope, very long term. But there was concern that the AIs, being non-human after all and running on an entirely different substrate, would not share humanity’s concern for its own well-being, and would pursue different agendas. So a new approach to emulating human-level AI was tried out. Volunteers were sought—or rather, the hyper-rich of the Heroic Generation competed for places—”

“I was a Green Brain experiment,” Earthshine said. “Major Kalinski, I was reverse-engineered as an AI. My name is—was—Robert Braemann. I grew up in North Britain, as it is known now. They opened up my head and modelled the hundred billion neurones, the quadrillion synapses, in a vast software suite that was itself state-of-the-art. It was done by nanoprobes crawling through my skull, multiplying, reporting… I was brought back to consciousness repeatedly, to monitor the process. I, I, felt nothing.”

Stef frowned. “They modelled every organic bit of you, or the essence of you. And you still claim to be you—whoever you were?”

Penny smiled. “Sis, you’ve put your finger on the paradox that troubles most of us, when you look at a Green Brain.”

“Don’t call me ‘sis’.”

“I considered calling myself Theseus. I doubt you’ve had time to read any Plutarch along with your quantum theory, Major. Theseus’s Paradox is this: Theseus’s ship had each of its component parts, the wood and the nails, replaced one by one, until the whole fabric was new. Is it the same ship? It is an old quandary.”

Stef thought it over. “If you define the ship by its function, it’s still the same ship. Or if you consider it as an object with an extension in time as well as space—”

“Yes. Quite so. There are different cultural responses to the paradox, interestingly. The Japanese, for example, in their unstable country, used to build their temples of wood, that could be regularly and readily rebuilt—yet the temple stays the same.” He smiled. “I had Japanese engineers manage my transition. While I lay there with my head opened up like a bucket of ice cream, I did not want my doctors to be paralysed by epistemological doubt.”

“Yes,” Penny said. “But in fact they didn’t just pour out one brain to make you, did they, Earthshine? Stef, he had nine donors. Nine parents. Think of that! So much for the Green Brain effort; all it gave us was a better interface to their inhumanity. Earthshine and his buddies plan for the long term, which is a good thing. But their vision of the long term is one that benefits them, ultimately, snug in their bunkers—”

“I did not bring you here to argue over the justification for my own existence,” Earthshine said. “I can only assure you that whatever you think of me, on some level I remain human enough to sympathise with how you must feel at a moment like this.” He pointed. “Your father’s grave is just over there.”

They found it easily, only a few years old, a modest memorial beside the decades-old grave of their mother.

Penny said, “Weird for both of us, right? We supported each other, that day.”

“No,” Stef said. She turned away from her sister.

Earthshine stood now—the three chairs, empty, winked out of existence behind him—and he walked across to join them.

Stef said, “Earthshine, tell me what we’re supposed to see here.”

“No,” Penny snapped. “First, tell us what it is you want of us.”

“I want you to be my allies,” Earthshine said simply.

“Because?”

“Because he’s afraid,” Stef said. “He told us that. But afraid of what?”

“Of all this.” He waved a hand. “As you remarked, we AIs differ from you humans—even I, more like you than my siblings—in that we think on long timescales. That is a distinction. And on the longest of timescales, what is there not to fear? We are motes, our very worlds are motes, floating in a universe that was born of unimaginable violence. Our little corner of the universe is tranquil enough now, relatively. But it was not always this way, and why should it remain so? What if our world, the universe itself, is destined to die in violence too, die of ice or fire? That would at least have a certain symmetry to the telling, wouldn’t it?

“And what if we bring that violence down on ourselves? War is the wolf that has stalked mankind since before our ancestors left the trees. Though it’s largely gone unnoticed, my Core brothers and I have been working hard, mainly by influencing human agencies like the UN and the governing councils of the Chinese Greater Economic Framework, to bind up the wolf of war with treaties, with words. And we’ve largely succeeded, so far. Well, the fact that we stand here in the simulated sunshine having this conversation is proof of that. But now we are an interplanetary civilisation. That wolf, if it got loose now, if it got a chance, could smash whole worlds—it could have done that even before we stumbled across these kernels of yours…

“But the kernels exist, and now we have a new factor to deal with—a new randomness. This strange discovery at the heart of the solar system, the kernels, this Hatch that leads nowhere—nowhere but to this, a raggedly changed reality. What power implanted the kernels and created the Hatch? What power is now meddling with our history? Who is it? What does it want? How can we deal with it? The very existence of these alien toys is destabilising—surely you can see that? And the more we discover of their power, the more destabilising they become.”

Stef said, “You want us to work with you.”

“I need allies,” Earthshine said. “We do, the three of us in the Core. Human allies. You have kept kernel physics from us; perhaps that is wise. Our priority now is to prevent these new discoveries sparking a devastating war. And if it turns out that the Hatch-makers really do have the power to meddle with our history…”

Penny asked, a little wildly, “And you brought us here because you have proof of that?”

He pointed. “Look at your mother’s headstone. Can you read French? Let me translate. Here lies Juliette Pontoin, born—well, you know the dates—accomplished chemist, wife to George Kalinski, beloved mother of Stephanie Penelope Kalinski…”

Mother of Stephanie Penelope Kalinski. Not of Stephanie Karen and Penelope Dianne. One name only. One true name.

Penny was staring at the stone. She looked devastated. She had lost a piece of her own past, and Stef knew how that felt.

Stef turned to Earthshine. “Another ragged edge.”

“Yes. Now you see—we must work together. Over the years to come. We must keep in touch. Study this, in the background of our other projects.”

“Yes,” Stef said automatically.

Penny seemed too stunned to respond.

“And when we discover who is responsible for this…” Earthshine stepped forward, staring at the stone. “I am everywhere. And I am starting to hear your footsteps, you Hatch-makers. I can hear the grass grow. And I can hear you.”