Xeelee: Endurance

by Stephen Baxter

  ‘Yes.’ Miriam grinned. ‘It would feel like a voyage in the Crab. Our observer will feel safe, in control. I’ll get to work on it . . .’

  I said, ‘OK. So you’re planning to project a Virtual copy of one of us through the wormhole. And how will you get him or her back?’

  They looked at me, as if I’d asked yet another foolish question.

  ‘That won’t be possible,’ Poole said. ‘The unit will be lost. It’s possible we could transmit back a copy of the memories the Virtual accrues on the other side – integrate them somehow with the backup in the GUTengine’s other store—’

  ‘No,’ Harry said regretfully. ‘The data rate through that interface would never allow even that. For the copy in there it’s a one-way trip.’

  ‘Well, that’s entirely against the sentience laws,’ I put in. They ignored me. But to point this out was, after all, my paid job.

  Poole said, ‘That’s settled, then. The question is, who? Which of the four of us are we going to wake up from cyber-sleep and send into the unknown?’

  I noticed that Harry’s disembodied floating head looked away, as if he were avoiding the question.

  Poole and Miriam looked at each other.

  ‘We should give it to Bill,’ Miriam said firmly.

  ‘Yeah. There’s no other choice. Bill’s gone, and we can’t bring his stored backup home with us . . . We should let his backup have the privilege of doing this. It will make the sacrifice worthwhile.’

  I stared at them. ‘This is the way you treat your friends? By killing them, reviving backups and sending them to another certain death?’

  Poole glared at me. ‘Bill won’t see it that way, believe me. You and a man like Bill Dzik have nothing in common, Emry. Don’t judge him by your standards.’

  ‘Fine. Just don’t send me.’

  ‘Oh, I won’t. You don’t deserve it.’

  It took them only a few more minutes to prepare for the experiment. The control pack didn’t need any physical modifications, and it didn’t take Miriam long to programme instructions into its limited onboard intelligence. She provided it with a short orientation message, in the hope that Virtual Bill wouldn’t be left entirely bewildered at the sudden transition he would experience.

  Poole picked up the pack with his gloved hands, and walked towards the interface, or as close as Harry advised him to get. Then Poole lifted the pack over his head. ‘Good luck, Bill.’ He threw the pack towards the interface – or rather pushed it; its weight was low but its inertia was just as it would have been on Earth, and besides Poole had to fight against the resistance of the syrupy sea. For a while it looked as if the pack might fall short. ‘I should have practised a couple of times,’ Poole said ruefully. ‘Never was any use at physical sports . . .’

  But he got it about right. The pack clipped the rim of the hole, then tumbled forward and fell slowly, dreamlike, through that black surface. As it disappeared, autumn gold glimmered around it.

  Then we had to wait, the three of us plus Harry. I began to wish that we had agreed some time limit; obsessives like Poole and Miriam were capable of standing there for hours before admitting failure.

  In the event it was only minutes before a scratchy voice sounded in our suit helmets. ‘Harry? Can you hear me?’

  ‘Yes!’ Harry called, grinning. ‘Yes, I hear you. The reception ought to get better, the clean-up algorithms are still working. Are you all right?’

  ‘Well, I’m sitting in the Crab lifedome. It’s kind of a shock to find myself here, after bracing my butt to enter Titan. Your little orientation show helped, Miriam.’

  Poole asked, ‘What do you see?’

  ‘The sky is . . . strange.’

  Miriam was looking puzzled. She turned and looked at Harry. ‘That’s not all that’s strange. That’s not Bill!’

  ‘Indeed not,’ came the voice from the other side of the hole. ‘I am Michael Poole.’

  14

  So, while a suddenly revived Michael Poole floated around in other-space, the original Poole and his not-lover Miriam Berg engaged in a furious row with Harry. Despite the circumstances, I found all this amusing.

  Poole stormed over to the GUTengine’s remaining control pack, and checked the memory’s contents. It had never contained backup copies of the four of us after all; it contained only one ultra-high-fidelity copy, of Michael Poole himself. I could not decide which scared me more: the idea that no copies of myself existed in that glistening white box, or the belief I had entertained previously that there had. I am prone to existential doubt, and am uncomfortable with such notions.

  But such subtleties were beyond a raging Michael Poole. ‘Miriam, I swear I knew nothing about this.’

  ‘Oh, I believe you.’

  They both turned on the older Poole. ‘Harry?’ Michael snapped. ‘What in Lethe did you do?’

  Disembodied-head Harry looked shifty, but he was going to brazen it out. ‘As far as I’m concerned there’s nothing to apologise for. The storage available on the Crab was always limited, and it was worse in the gondola. Michael’s my son. Of course I’m going to protect him above others. What would you do? I’m sorry, Miriam, but—’

  ‘You aren’t sorry at all,’ Miriam snapped. ‘And you’re a cold-hearted bastard. You knowingly sent a backup of your son, who you say you’re trying to protect, through that wormhole to die!’

  Harry looked uncomfortable. ‘It’s just a copy. There are other backups, earlier copies—’

  ‘Lethe, Dad,’ Michael Poole said, and he walked away, bunching his fists. I wondered how many similar collisions with his father the man had had to suffer in the course of his life.

  ‘What’s done is done,’ came a whisper. And they all quit their bickering, because it was Michael Poole who had spoken – the backup Poole, the one recently revived, the one beyond the spacetime barrier. ‘I know I don’t have much time. I’ll try to project some imagery back . . .’

  Harry, probably gratefully, popped out of existence, thus vacating the available processing capacity, though I was sure his original would be monitoring us from the Crab.

  Poole murmured to Miriam, ‘You speak to him. Might be easier for him than having to deal with me.’

  She clearly found this idea distressing. But she said, ‘All right.’

  Gradually images built up in the air before us, limited views grainy with pixels and flickering.

  And we saw Virtual Poole’s strange universe.

  The Virtual Crab floated over a small object – like an ice moon, like one of Titan’s Saturnian siblings, pale and peppered with worn impact craters. I saw how its surface was punctured with holes, perfectly round and black. These looked like our hatch; the probe we had dispatched must have emerged from one of them. Things that looked like our spiders toiled to and fro between the holes, travelling between mounds of some kind of supplies. They were too distant to see clearly. All this was bathed in a pale-yellow light, diffuse and without shadows.

  The original Poole said, ‘You think those other interfaces connect up to the rest of Titan?’

  ‘I think so,’ Miriam said. ‘This can’t be the only deep-sea methane-generation chamber. Passing through the wormholes and back again would be a way for the spiders to unify their operations across the moon.’

  ‘So the interface we found, set in the outer curved surface of Titan’s core, is one of a set that matches another set on the outer curved surface of that ice moon. The curvature would seem to flip over when you passed through.’

  This struck me as remarkable, a paradox difficult to grasp, but Poole was a wormhole engineer, and used to the subtleties of spacetime manipulated and twisted through higher dimensions; slapping two convex surfaces together was evidently child’s play to him, conceptually.

  Miriam asked Virtual Poole, ‘But where are you? That’s an ice moon, a common object. Could
be anywhere in the universe. Could even be in some corner of our own System.’

  Poole’s Virtual copy said, his voice a whispery, channel-distorted rasp, ‘Don’t jump to conclusions, Miriam. Look up.’

  The viewpoint swivelled, and we saw Virtual Poole’s sky.

  A huge, distorted sun hung above us. Planetoids hung sprinkled before its face, showing phases from crescents to half-moons; some were entirely black, fly-speck eclipses against the face of the monster. Beyond the limb of the sun more stars hung, but they were also swollen, pale beasts, their misshapen discs visible. And the space between the stars did not look entirely black to me, but a faint, deep crimson overlaid with a pattern, a network of threads and knots.

  ‘What a sky,’ Poole murmured.

  ‘Michael, you’re far from home,’ Miriam called.

  Virtual Poole replied, ‘Yes. Those stars don’t fit our main sequence. And their spectra are simple – few heavy elements. They’re more like the protostars of our own early universe, I think: the first generation, formed of not much more than the hydrogen and helium that came out of the Big Bang.’

  ‘No heavy elements,’ observed Miriam Berg. ‘No metals.’

  ‘I’ll send through the data I’m collecting—’

  ‘Getting it, son,’ came Harry Poole’s voice.

  The others stayed quiet to let Virtual Poole speak. His words, the careful observations delivered by a man so far from home, or at least by a construct that felt as if it were a man, were impressive in their courage.

  ‘This is not our universe,’ he whispered. ‘I think that’s clear. This one is young, and small – according to the curvature of spacetime, only a few million light years across. Probably not big enough to accommodate our Local Group of galaxies.’

  ‘A pocket universe, maybe,’ Miriam said. ‘An appendix from our own.’

  ‘I can’t believe the things you have been calling “spiders” originated here,’ the Virtual said. ‘Their fabric is heavily reliant on metals. You said it, Miriam. No metals here, not in this entire cosmos. I guess that’s why they were scavenging metals from probes, meteorites.’

  ‘They come from somewhere else, then,’ Poole said. ‘There was nothing strange in the elemental abundance we recorded in the spider samples we studied. They come from elsewhere in our own universe. The pocket universe is just a transit interchange. Like Earthport.’

  The Virtual said, ‘Yes. And maybe behind these other moons in my sky lie gateways to other Titans – other sustained ecologies, maybe with different biological bases. Other experiments, elsewhere in the universe.’

  Miriam said, ‘So if metals are so essential for the spiders, why not have supplies brought to them through the interchange?’

  ‘Maybe they did, once,’ the Virtual said. ‘Maybe things broke down. There’s a sense of age here, Miriam. This is a young cosmos maybe, but I think this is an old place . . .’

  The real Poole murmured, ‘It makes sense. The time axis in the baby universe needn’t be isomorphic with ours. A million years over here, a billion years there.’

  The Virtual whispered, ‘Those spiders have been toiling at their task on Titan a long, long time. Whoever manufactured them, or bred them, left them behind a long time ago, and they’ve been alone ever since. Just doing their best to keep going. Looking at them, I get the impression they aren’t too bright. Just functional.’

  ‘But they did a good job,’ Miriam said.

  ‘That they did.’

  ‘But why?’ I blurted out. ‘What’s the purpose of all this, the nurturing of an ecology on Titan for billions of years – and perhaps similar on a thousand other worlds?’

  ‘I think I have an idea,’ Virtual Poole said. ‘I never even landed on Titan, remember. Perhaps, coming at all this so suddenly, while the rest of you have worked through the stages of your discovery, I see it differently . . .

  ‘Just as this pocket universe is a junction, so maybe Titan is a junction – a haven where different domains of life can coexist. And it’s been designed that way.

  ‘You’ve found the native ammono fish, the CHON sponges that may originate in the inner System, and the silanes from Triton or beyond. Maybe there are other families to find, if you had time to look. All these kinds of life, arising from different environments – but all with one thing in common. All born of planets, and of skies and seas, in worlds warmed by stars.

  ‘But the stars won’t last for ever. In the future the universe will change, until it resembles our own time even less than our universe resembles this young dwarf cosmos. What then? Look, if you were concerned about preserving life, all forms of life, into the very furthest future, then perhaps you would promote—’

  ‘Cooperation,’ said Miriam Berg.

  ‘You got it. Symbiosis. Maybe Titan is a kind of prototype, a forced cooperative ecology where life forms of such different origins are compelled to mix, to find ways of using each other to survive—’

  ‘And ultimately merge, somehow,’ Miriam said. ‘Well, it’s happened before. Each of us is a community, with once-disparate and very different life forms toiling away in each of our cells. It’s a lovely vision, Michael.’

  ‘More important than that, it’s plausible,’ Poole’s original self said gruffly. ‘Anyhow it’s a hypothesis that will do until something better comes along.’

  I sneered at that. This dream of cosmic cooperation struck me as the romantic fantasy of a man alone and doomed to die, and soon. We all project our petty lives upon the universe. But I had no better suggestions to make. And, who knows? Perhaps Virtual Poole was right. None of us will live to find out.

  ‘Anyhow,’ I said, ‘charming as this is – are we done now?’

  Miriam snapped, ‘We can’t abandon Michael.’

  ‘Go,’ whispered Virtual Poole. ‘There’s nothing you can do for me. I’ll keep observing, reporting, as long as I can.’

  I gagged on his nobility.

  Now Harry intruded, grabbing a little of the available Virtual projection capacity. ‘But we’ve still got business to conclude before you leave here.’

  15

  Poole frowned. ‘What business?’

  ‘We came here to prove that Titan is without sentience,’ Harry said. ‘Well, we got that wrong. Now what?’

  Miriam Berg was apparently puzzled we were even having the conversation. ‘We report what we’ve found to the sentience oversight councils and elsewhere. It’s a major discovery. We’ll be rapped for making an unauthorised landing on Titan, but—’

  ‘Is that the sum of your ambition?’ I snapped. ‘To hope the authorities will be lenient if you reveal the discovery that is going to ruin you?’

  She glared at me. ‘What’s the choice?’

  ‘Isn’t it obvious?’ I looked at her, and Poole, who I think was guessing what I was going to say, and Harry, who turned away as he usually did at moments of crisis. Suddenly, after days of existential terror and pointless wonders, I was in my own element, which is the murky world of human relationships, and I could see a way forward where they could not. ‘Destroy this,’ I said. I waved a hand. ‘All of it. You have your grenades, Miriam. You could bring this cavern down.’

  ‘Or,’ Harry said, ‘there is the GUTengine. If that were detonated, if unified-field energies were loosed in here, the wormhole interface too would surely be disrupted. I’d imagine that the connection between Titan and the pocket universe would be broken altogether.’

  I nodded. ‘I hadn’t thought of that, but I like your style, Harry. Do it. Let this place be covered up by hundreds of kilometres of ice and water. Destroy your records. It will make no difference to the surface, what’s going on in the atmosphere, not immediately. Nobody will ever know all this was here.’

  Harry Poole said, ‘That’s true. Even if methane generation stops immediately, the residual would persist in the atmosphere f
or maybe ten million years. I venture to suggest that if the various multi-domain critters haven’t learned to cooperate in that time, they never will. Ten megayears is surely enough.’

  Miriam looked at the bizarrely drifting head, horrified by his words. ‘You’re suggesting a monstrous crime,’ she breathed. ‘To think of destroying such a wonder as this, a billion-year project – to destroy it for personal gain! Michael, Lethe, leave aside the morality, surely you’re too much of a scientist to countenance this.’

  But Poole sounded anguished. ‘I’m not a scientist any more, Miriam. I’m an engineer. I build things. I think I sympathise with the goals of the spider makers. What I’m building is a better future for the whole of mankind – that’s what I believe. And if I have to make compromises to achieve that future . . . well. Maybe the spider makers had to make the same kind of choices. Who knows what they found here on Titan before the makers went to work on it – who knows what potential they destroyed?’

  And in that little speech, I believe, you have encapsulated both the magnificence and the grandiose folly of Michael Poole. I wondered then how much damage this man might do to us all in the future, with his wormholes and his time-hopping starships – what horrors he, blinded by his ambition, might unleash.

  Harry said unexpectedly, ‘Let’s vote on it. If you’re in favour of destroying the chamber, say yes.’

  ‘No!’ snapped Miriam.

  ‘Yes,’ said Harry and Poole together.

  ‘Yes,’ said I, but they all turned on me and told me I didn’t have a vote.

  It made no difference. The vote was carried. They stood looking at each other, as if horrified by what they had done.

  ‘Welcome to my world,’ I said cynically.

  Poole went off to prepare the GUTengine for its last task. Miriam, furious and upset, gathered together our equipment, such as it was, her pack with her science samples, our tangles of rope.