'Why did you let me do it?' she said.

The mathematics gave its equivalent of a shrug. 'You weren't ready to listen.'

'Take us back there.'

'I wouldn't recommend that.'

'Take us back.'

The White Cat shut her torch down and fell as silently as a derelict between the gas giants. Course changes were made in increments, using tiny, ferocious pSi engines which worked by blowing oxygen on to porous silicon compounds. Meanwhile, the particle-detectors and massive arrays, extending like veinous systems in a leaf, sifted vacuum for the track of the Krishna Moire pod. Tower up,' the mathematics instructed quietly. 'Power down.' What was left of Seria Mau's body moved impatiently in its tank. She had a need to see Billy Anker that anyone else would have described as physical. If she had remembered how, she would have bitten her lip. 'Why did I do this?' she asked herself. The shadow operators shook their heads: sooner or later something like it had been bound to happen, they inferred. In the end the White Cat got close enough to examine the planet itself. Something moved among the feathers. It might have been whatever lived down there; it might have been ancient calculations crumbling into dust.

'What's that?' said the mathematics.

'Nothing,' said Seria Mau. 'Go in,' she ordered. 'I've had enough of this.'

She found Billy Anker and Mona the clone lying half out of the long cobalt shadows. Mona was already dead, her pretty blonde head resting on the upper part of Billy's chest. He had one arm round her shoulders. With his other hand he was still stroking her hair. As she died she had been looking intently into his face, and had placed one leg between both his, trying to get some final comfort out of life. Under the instructions of the old algorithm-which, provided so suddenly with raw material for its endless repetition, had sifted stealthily down on to them from the structures above-their cells were turning to feathers. Billy Anker's legs looked like a peacock satyr's. Mona was gone all the way to diaphragm, blue-black dusty feathers which seemed to shift and grow and do something odd to the light.

Seria Mau's fetch-in these conditions little more than a shadow itself -wove nervously about in front of the lovers. How could I have done this? she thought, while she said aloud:

'Billy Anker, is there any way I can help?'

Billy Anker never stopped stroking the dead woman's hair, or looking away from her.

'No,' he said.

'Does it hurt?'

Billy Anker smiled to himself. 'Kid,' he said, 'it's more comfortable than you'd think. Like a good downer.' He laughed suddenly. 'Hey, the wormhole was the spectacle. You know? That's what I keep remembering. That was how I expected to go.' Silent a moment, he contemplated that. 'I could never even describe what it was like in there,' he said. Then he said, 'I can hear this thing counting. Or is that some sort of illusion?'

Seria Mau came as close to him as she could.

'I can't hear anything. Billy Anker, I'm sorry to have done this.' At that, he bit his lip and finally looked away from Mona the clone.

'Hey,' he said. 'Forget it.'

He convulsed. Dust billowed up from the stealthily shifting surface of his body. The algorithm was reorganising him at all scales. For a moment his eyes filled with horror. He hadn't expected this. 'It's eating me!' he shouted. He flailed with his arms, clutched at the dead woman as if she might help him. Forgetting she was only a fetch, he tried to clutch at Seria Mau too. Then he got control of himself again. 'The more you deny the forces inside, kid, the more they control you,' he said. His hand went through her like a hand through srnoke. He stared at it in surprise. 'Is this happening?' he asked.

'Billy Anker, what am I to do?'

'That ship of yours. Take it deep. Take it to the Tract.'

'Billy, I-'

Above them, streaks of violet ionisation went across the face of the gas giant. There was a great whistling thud of displaced air; then another; then a vast emerald fireball somewhere in orbit, as the White Cat began to defend herself against what must be the attentions of the Krishna Moire pod. Suddenly, Seria Mau was half up there with her ship, half down here with Billy Anker. Alarms were going off everywhere along the continuum between these two states, and the mathematics was trying to disconnect her fetch.

'Leave me!' she cried. 'I want to stay with him! Someone must stay with him!'

Billy Anker smiled and shook his head.

'Get out of here, kid. That's Uncle Zip up there. Get out while you can.'

'Billy Anker, I brought them down on you!'

He looked tired. He closed his eyes.

'I brought them down on myself, kid. Get out of here. Take it deep.'

'Goodbye, Billy Anker.'

'Hey, kid-'

But when she turned to answer, he was dead.

I fell for it, she told herself in despair. All the fucking and the fighting. Despite everything I promised myself, I fell for it too.

Then she thought: Uncle Zip! Terror dissolved her, because she had so underestimated that fat man, how intelligent he was, how galaxywide. She had been in his hands from the moment she began to deal with him.

What would she do now?

TWENTY-FOUR

Tumbling Dice

'If I'm predicting the future, how come I always see the past?'

When Ed asked Sandra Shen that question, she was no more help than Annie Glyph. All she did was shrug lightly.

'I think we need practice, Ed,' she said. She lit a cigarette and gave her attention amusedly to something in the corner of the room. 'I think we need to work harder.'

Ed never could decode that distant look of hers. If anything, she seemed pleased by the debacle in the main tent. It filled her full of energy: her other projects languished, and she was around on a daily basis. She kicked the old men out of the bar of the Dunes Motel. He came in and found her fitting it out with equipment of her own, which she was bringing in at night in unmarked crates. This stuff was uniformly old. It featured cloth-covered electric cable, Bakelite casings, dials across which tiny needles rose and fell. There was some kind of amplifier that worked by valves.

'Jesus,' he said. 'This is real.'

'Fun, isn't it?' Sandra Shen said. 'Four hundred and fifty years old, give or take. Ed, it's time we began to work together on this. Put our heads together. What I need to do is fasten these straps round your wrists… '

The idea was that Ed sat with his arms and legs strapped to the arms and legs of a big raw-looking wooden chair that came with the rest of the equipment, while Sandra Shen connected herself to the valve amplifier. She then settled the fishtank on Ed's head and asked him questions until she got an answer that suited her. Her voice came to him close and intimate, as if she was in there with him and the eels on their weird, tiring journey beneath the Alcubiere sea, forward towards some unwelcome revelation of his youth. The questions were meaningless to Ed.

'Is life a bitch or isn't it, Ed?' she would say. Or: 'Can you count to twelve?'

He never heard his own answers anyway. The part of him inside the fishtank wasn't hooked up to the part outside: not in any way as simple as that. The bar at the Dunes Motel lay in its baking afternoon darkness, split by a single ray of whitesunlight. The oriental woman leaned against the bar, smoked, nodded to herself. When she got an answer that suited her, she cranked a handle on her apparatus. Curious bluish jolts of light were emitted undependably from its cathodes. The man in the chair convulsed and screamed.

In the evenings, Ed still had to give his performance. He was exhausted. Audiences dwindled. Eventually, only Madam Shen, dressed in a frankly dйcolletй emerald cocktail dress, was there to watch. Ed began to suspect the audiences weren't the point of it. He had no idea what Sandra Shen wanted from him. When he tried to talk to her about it before the show, she only told him not to worry. 'More practice, Ed. That's all you need.' She sat in the best seats, smoking, applauding with soft claps of her little strong hands. 'Well done, Ed. Well done.'Afterwards two or three carnies would drag him away. Or if Annie happened to be around, she would pick him up with a kind of tender amusement and carry him back to her room.