"Isn't it obvious?" I looked at her, and Poole, who I think was guessing what I was going to say, and Harry, who looked away as he usually did at moments of crisis. Suddenly, after days of pointless wonders, I was in my element, 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." 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 GUTdrive. 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 t.i.tan 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 kilometers of ice and water. Destroy your records. It will make no difference to the surface, what's going on in the atmosphere, not immediately. n.o.body 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 for 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 him, horrified by his words. "You're suggesting a monstrous crime," she breathed. "To think of destroying such a wonder as this, the product of a billion years 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 anymore, Miriam. I'm an engineer. I build things. I think I sympathize 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 t.i.tan before they went to work on it..."

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 vision, might unleash.

Harry said unexpectedly, "Let's vote on it. If you're in favor 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 GUT engine 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.

And Harry popped into the air in front of me. "Thanks," he said.

"You wanted me to make that suggestion, didn't you?"

"Well, I hoped you would. If I'd made it they'd have refused. And Michael would never have forgiven me." He grinned. "I knew there was a reason I wanted to have you along, Jovik Emry. Well done. You've served your purpose."

Virtual Poole, still in his baby universe, spoke again. "Miriam."

She straightened up. "I'm here, Michael."

"I'm not sure how long I have left. What will happen when the power goes?"

"I programmed the simulation to seem authentic, internally consistent. It will be as if the power in the Crab Crab life-dome is failing." She took a breath, and said, "Of course you have other options to end it before then." life-dome is failing." She took a breath, and said, "Of course you have other options to end it before then."

"I know. Thank you. Who were they, do you think? Whoever made the spiders. Did they build this pocket universe too? Or was it built for built for them? Like a haven?" them? Like a haven?"

"I don't suppose we'll ever know. Michael, I'm sorry. I "

"Don't be. You know I would have chosen this. But I'm sorry to leave you behind. Miriam-look after him. Michael. I, we, need you."

She looked at the original Poole, who was working at the GUT engine. "We'll see," she said.

"And tell Harry-well. You know."

She held a hand up to the empty air. "Michael, please "

"It's enough." The Virtuals he had been projecting broke up into blocks of pixels, and a faint hiss, the carrier of his voice, disappeared from my hearing. Alone in his universe, he had cut himself off.

The original Poole approached her, uncertain of her reaction. "It's done. The GUT engine has been programmed. We're ready to go, Miriam. Soon as we're out of here "

She turned away from him, her face showing something close to hatred.

XVI Ascension

So, harnessed to a spider oblivious of the impending fate of its vast and ancient project, we rose into the dark. It had taken us days to descend to this place, and would take us days to return to the surface, where, Harry promised, he would have a fresh balloon waiting to pick us up.

This time, though I was offered escape into unconsciousness, I stayed awake. I had a feeling that the last act of this little drama had yet to play itself out. I wanted to be around to see it.

We were beyond the lower ice layers and rising through 250 kilometers of sea when Miriam's timer informed us that the GUT engine had detonated, far beneath us. Insulated by the ice layer, we felt nothing. But I imagined that the spider that carried us up towards the light hesitated, just fractionally.

"It's done," Poole said firmly. "No going back."

Miriam had barely spoken to him since the cavern. She had said more words tome. Now she said, "I've been thinking. I won't accept it, Michael. I don't care about you and Harry and your d.a.m.n vote. As soon as we get home I'm going to report what we found." Now she said, "I've been thinking. I won't accept it, Michael. I don't care about you and Harry and your d.a.m.n vote. As soon as we get home I'm going to report what we found."

"You've no evidence "

"I'll be taken seriously enough. And someday somebody will mount another expedition, and confirm the truth."

"All right." That was all he said. But I knew the matter was not over. He would not meet my mocking eyes.

I wasn't surprised when, twelve hours later, as Miriam slept cradled in the net draped from the spider's back, Poole took vials from her pack and pressed them into her flesh, one by a valve on her leg, another at the base of her spine.

I watched him. "You're going to edit her. Plan this with Dad, did you?"

"Shut up," he snarled, edgy, angry.

"You're taking her out of her own head, and you'll mess with her memories, with her very personality, and then you'll load her back. What will you make her believe-that she stayed up on the Crab Crab with Harry the whole time, while you went exploring and found nothing? That would work, I guess." with Harry the whole time, while you went exploring and found nothing? That would work, I guess."

"I've got nothing to say to you."

But I had plenty to say to him. I am no saint myself, and Poole disgusted me as only a man without morality himself can be disgusted. "I think you love her. I even think she loves you. Yet you are prepared to mess with her head and her heart, to serve your grandiose ambitions. Let me tell you something. The Poole she left behind in that pocket universe, the one she said goodbye to, he was a better man than you will ever be again. Because he was not tainted by the great crime you committed when you destroyed the cavern. And because he was not tainted by this. by this.

"And let me make some predictions. No matter what you achieve in the future, Michael Poole, this crime will always be at the root of you, gnawing away. And Miriam will never love you. Miriam will never love you. Even though you wipe out her memory of these events, there will always be something between you; she will sense the lie. She will leave you, and then you will leave her. And you have killed t.i.tan. One day, millions of years into the future, the very air will freeze and rain out, and everything alive here will die. All because of what you have done today. And, Poole, maybe those whose work you have wrecked will some day force you to a reckoning." Even though you wipe out her memory of these events, there will always be something between you; she will sense the lie. She will leave you, and then you will leave her. And you have killed t.i.tan. One day, millions of years into the future, the very air will freeze and rain out, and everything alive here will die. All because of what you have done today. And, Poole, maybe those whose work you have wrecked will some day force you to a reckoning."

He was open, defenceless, and I was flaying him. He had no answer. He cradled the unconscious Miriam, even as his machines drained her memory.

We did not speak again until we emerged into the murky daylight of t.i.tan.

EPILOGUE.

Probe

It didn't take Michael long to check out the status of his fragile craft.

The power in the lifetime's internal cells might last what, a few hours? As far as he could tell there was no functional link between the dome and the rest of the Hermit Crab; Crab; none of his controls worked. Maybe that was beyond the scope of Miriam's simulation. So he had no motive power. none of his controls worked. Maybe that was beyond the scope of Miriam's simulation. So he had no motive power.

He didn't grouse about this, nor did he fear his future. Such as it was.

The universe beyond the lifedome was strange, alien. The toiling spiders down on the ice moon seemed like machines, not alive, not sentient. He tired of observing them. He turned on lights, green, blue. The lifedome was a little bubble of Earth, isolated.

Michael was alone, in this whole universe. He could feel it.

He got a meal together. Miriam's simulation was good, here in his personal s.p.a.ce; he didn't find any limits or glitches. Lovingly constructed, he thought. The mundane ch.o.r.e, performed in a bright island of light around the lifetime's small galley, was oddly cheering.

He carried the food to his couch, lay back with the plate balancing on one hand, and dimmed the dome lights. He finished his food and set the plate carefully on the floor. He drank a gla.s.s of clean water.

Then he went to the freefall shower and washed in a spray of hot water. He tried to open up his senses, to relish every particle of sensation. There was a last time for everything, for even the most mundane experiences. He considered finding some music to play, a book to read. Somehow that might have seemed fitting.

The lights failed. Even the instrument slates winked out.

Well, so much for music. He made his way back to his couch. Though the sky was bright, illuminated by the proto-sun, the air grew colder; he imagined the heat of the life-dome leaking out. What would get him first, the cold, or the failing air?

He wasn't afraid. And he felt no regret that he had lost so much potential life, all those AS-extended years. Oddly, he felt renewed: young, for the first time in decades, the pressure of time no longer seemed to weigh on him.

He was sorry he would never know how his relationship with Miriam might have worked out. That could have been something. But he found, in the end, he was glad that he had lived long enough to see all he had.

He was beginning to shiver, the air sharp in his nostrils. He lay back in his couch and crossed his hands on his chest. He closed his eyes.

A shadow crossed his face.

He opened his eyes, looked up. There was a ship hanging over the lifedome.

Michael, dying, stared in wonder.

It was something like a sycamore seed wrought in jet black. Night-dark wings which must have spanned hundreds of kilometers loomed over the Crab, Crab, softly rippling. softly rippling.

The cold sank claws into his chest; the muscles of his throat abruptly spasmed, and dark clouds ringed his vision.

Not now, he found himself pleading silently, his failing vision locked onto the ship, all his elegiac acceptance gone in a flash. Just a little longer. I have to know what this means. Please Just a little longer. I have to know what this means. Please Poole's consciousness was like a guttering candle flame. Now it was as if that flame was plucked from its wick. That flame, with its tiny fear, its wonder, its helpless longing to survive, was spun out into a web of quantum functions, acausal and nonlocal.

The last heat fled from the craft; the air in the translucent dome began to frost over the comms panels, the couches, the galley, the p.r.o.ne body. And the ship and all it contained, no longer needed, broke up into a cloud of pixels.

REMEMBRANCE.

"I am the Rememberer," said the old man. "The last in a line centuries long. This is what was pa.s.sed on to me, by those who remembered before me.

"Harry Gage was on Earth when the Squeem came..."

As he talked, Rhoda Voynet glanced around at her staff. Soldiers all, the planes of their faces bathed in golden Saturn light, they listened silently.

The old man was a Virtual, projected from a police station on Earth, and the sunlight that shone on his face was much stronger than the diminished glow that reached this far orbit. Rhoda felt obscurely jealous of its warmth.

"Harry was born on Mars, in the Cydonia arcology. His great-grandparents were from Earth. There was a lot of that, in those days, before the Squeem. Everybody was mobile. Everything was opened up. Anything was possible.

"Harry's parents brought him to Earth, a once-in-a-lifetime trip to meet great-grandma and grandpa. He never did get to see them."

It had been the year 4874, nearly two centuries past. Harry Gage was ten years old.

And Earth was about to be conquered.

The flitter bearing Harry Gage and his parents had tumbled out of the shimmering throat of the wormhole transit route from Mars to Earthport.

Harry peered out of the cramped cabin, looking for Earth. Mum sat beside him, a bookslate on her lap, and Dad sat opposite, grinning at Harry's reaction. Harry would always remember these moments well.

Earthport was at one of the five gravitationally stable Lagrange points in the Earth-Moon system, leading the Moon in its...o...b..t around Earth by sixty degrees. The flitter surged unhesitatingly through swarming traffic. From here, Earth was a swollen blue disk. Wormhole gates of all sizes drifted across the face of the planet, electric-blue sculptures of exotic negative-energy matter.

The final hop to Earth itself took only a few hours. Soon the old planet, pregnant and green, was approaching, as if surfacing. Huge fusion stations, constructed from ice moons, sparkled in orbit above green-blue oceans.

The planet itself was laced with lights, on land and sea. In the thin rim of atmosphere near the north pole, Harry could just make out the dull purple glow of an immense radiator beam, a diffuse refrigerating laser dumping a fraction of Earth's waste heat into the endless sink of s.p.a.ce.

Earth was visibly stable, healthy, recovered from the climate-collapse horrors of the past, and managed by a confident mankind.

"Harry's flitter landed in New York," the Rememberer said. "A s.p.a.ceship coming down in the middle of Manhattan. Imagine that!"

Harry and his parents emerged onto gra.s.s, a park, in the sunshine of a New York spring. Harry could see the shoulders of tall, very ancient skysc.r.a.pers at the rim of the park, interlaced by darting flitters.

Dad raised his face to the sun and breathed deeply. "Mmm. Cherry blossom and freshly cut gra.s.s. I love that smell."

Mum snorted. "We have cherry trees on Mars."

"Every human is allowed to be sentimental about a spring day in New York. It's our birthright. Look at those clouds, Harry. Aren't they beautiful?"

Harry looked up. The sky was laced by high, fluffy, dark clouds, fat with water, unlike any on Mars. And beyond the clouds he saw crawling points of light: the habitats and factories of near-Earth s.p.a.ce. Harry was thrilled to the core.