I said honestly, "I have no idea what you're talking about."

"The idea you've suggested to them," Harry said gently, "is to revive one of the dormant ident.i.ty-backup copies in the unit's store, and use that use that as the controlling intelligence." as the controlling intelligence."

As always when they hit on some new idea Poole and Miriam were like two eager kids. Poole said, "It's going to be a shock to wake up, to move straight from t.i.tan entry to this point. It would be least disconcerting if we projected a full human animus."

"You're telling me," said the head of Harry Poole.

"And some enclosing environment," Miriam said. "Just a suit? No, to be adrift in s.p.a.ce brings in problems with vertigo. I'd have trouble with that."

"The lifedome of the Crab Crab," Poole said. "That would be straightforward enough to simulate to an adequate degree. And a good platform for observation. The power would be sufficient to sustain that for a few hours at least..."

"Yes." Miriam grinned. "Our observer will feel safe. I'll get to work on it..."

I asked, "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. "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 GUT engine'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.

Poole said, "That's settled, then. The question is,who? Which of the four of us are you going to wake up from cyber-sleep and send into the unknown?" Which of the four of us are you 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. Miriam said, "Either of us would go. Right?"

"Of course."

"But 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 friend? By killing him, then reviving a backup and sending it 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 program 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 hefted 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 practiced 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 Crab lifedome. It's kind of a shock to find myself here, after bracing my b.u.t.t to enter t.i.tan. Your little orientation show helped, Miriam." lifedome. It's kind of a shock to find myself here, after bracing my b.u.t.t to enter t.i.tan. 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."

XIV Virtual

So, while a suddenly revived Michael Poole floated around in other-s.p.a.ce, the original Poole and his not-lover Miriam Berg engaged in a furious row with Harry.

Poole stormed over to the GUT engine's remaining control pack, and checked the memory's contents. It didn't contain backup copies of the four of us; 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 p.r.o.ne to existential doubt, and am uncomfortable with such notions.

But such subtleties were beyond Michael Poole in his anger. "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 is this?"

Disembodied-head Harry looked shifty, but he was going to brazen it out. "As far as I'm concerned there's nothing to apologize for. The storage available on the Crab 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 " 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 b.a.s.t.a.r.d. You knowingly sent a backup of your son, who you say you're trying to protect, through that worm-hole 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 s.p.a.cetime 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. Crab.

Poole murmured to Miriam, "You speak to him. Might be easier for him than 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, flickering.

And we saw Virtual Poole's strange sky.

The Virtual Crab Virtual Crab floated over a small object-like an ice moon, like one of t.i.tan'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. floated over a small object-like an ice moon, like one of t.i.tan'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 t.i.tan?"

"I'd think so," Miriam said. "This can't be the only deep-sea methane-generation chamber. Pa.s.sing through the worm-holes 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 t.i.tan'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 pa.s.sed through."

This struck me as remarkable, a paradox difficult to grasp, but Poole was a wormhole engineer, and used to the subtleties of s.p.a.cetime 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, and 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 s.p.a.ce between the stars did not look entirely black to me, but a faint, deep crimson with a pattern, a network of threads and knots. It reminded me of what I saw when I closed my eyes.

"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 metals," observed Miriam Berg.

"I'll send through the data I'm collecting "

"Getting it, son," came Harry Poole's voice.

The others 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 s.p.a.cetime, 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. "You said it, Miriam. No metals here, not in this entire cosmos. That's why they were scavenging metals from probes, meteorites."

"They came from somewhere else, then," Poole said. "There was nothing strange in the elemental abundance we recorded in the spider samples we studied. So 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 t.i.tans-other sustained ecologies, maybe with different biological bases. Other experiments."

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 there, a billion years here."

The Virtual whispered, "Those spiders have been toiling at their task on t.i.tan 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 t.i.tan for billions of years and perhaps similar on a thousand other worlds?"

"I think I have an idea," Virtual Poole whispered. "I never even landed on t.i.tan, remember. Perhaps, coming at all this so suddenly, while the rest of you have worked through stages of discovery, I see it different...

"Just as this pocket universe is a junction, so maybe t.i.tan is a junction, a haven where different domains of life can coexist. You've found the native ammono fish, the CHON sponges that may originate in the inner system, perhaps even coming from Earth, and the silanes from Triton and 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 forever. 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. Maybe t.i.tan is a kind of prototype of an ecology where life forms of such different origins can mix, 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."

"And plausible," his 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 n.o.bility.

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

XV Resolution

Poole frowned. "What business?"

"We came here to prove that t.i.tan 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 t.i.tan, 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?"