'I just want some things,' Kearney said. 'It won't take long.'

'Michael -'

He pushed past her. The flat smelled strongly of incense and candle wax. To get to the room where he kept his stuff, he had to pass Anna's bedroom, the door of which was partly open. Tim, whoever he was, sat propped up against the wall at the head end of the bed, his face three-quarter profile in the yellow glow of two or three nightlight candles. He was in his mid thirties, with good skin and a build light but athletic, features which would help give him a boyish appearance well into his forties. He had a glass of red wine in one hand, and he was staring thoughtfully at it.

Kearney looked him up and down.

'Who the hell is this?' he said.

'Michael, this is Tim. Tim, this is Michael.'

'Hi,' said Tim. He held out his hand. 'I won't get up.'

'Jesus Christ, Anna,' Kearney said.

He went through to the back room, where a brief search turned up some clean Levis and an old black leather jacket he had once liked too much to throw away. He put them on. There was also a cycle-courier bag with the Marin logo on the flap, into which lie began emptying the contents of the little green chest of drawees. Looking up blankly from this task, he discovered that Anna had washed the chalked diagrams off the wall above it. He wondered why she would do that. He could hear her talking in the bedroom. Whenever she tried to explain anything, her voice took on childish, persuasive values. After a moment she seemed to give up and said sharply, 'Of course I don't! What do you mean?' Kearney remembered her trying to explain similar things to him. There was a noise outside the door and Tim poked his head round.

'Don't do that,' Kearney said. 'I'm nervous already.'

'I wondered if I could help?'

'No, thanks.'

'It's just that it's five o'clock in the morning, you see, and you come in here covered in mud.'

Kearney shrugged.

'I see that,' he said. 'I see that.'

Anna stood angrily by the door to watch him out. 'Take care,' he said to her, as warmly as he could. He was two nights down the stone stairs when he heard her footsteps behind him. 'Michael,' she called. 'Michael.' When he didn't answer, she followed him out into the street and stood there shouting at him in her bare feet and white nightdress. 'Did you come back for another fuck?' Her voice echoed up and down the empty suburban street. 'Is that what you wanted?'

'Anna,' he said, 'it's five o'clock in the morning.'

'I don't care. Please don't come here again, Michael. Tim's nice and he really loves me.'

Kearney smiled.

'I'm glad.'

'No, you're not!' she shouted. 'No, you're not!'

Tim came out of the building behind her. He was dressed, and he had his car keys in his hand. He crossed the pavement without looking at Anna or Kearney, and got into his car. He wound the driver's window down as if he thought about saying something to one of them, but in the end shook his head and drove off instead. Anna stared after him puzzledly then burst into tears. Kearney put his arm round her shoulders. She leaned in to him.

'Or did you come back to kill me,' she said quietly. 'The way you killed all those others?'

Kearney walked off towards the Underground station at Gunnersbury. His phone chirped at him suddenly, but he ignored it.

Heathrow Terminal 3, hushed after the long night, maintained a slow dry warmth. Kearney bought underwear and toilet articles, sat in one of the concessions outside the departure lounge reading the Guardian and taking small sips of a double espresso.

The women behind the concession counter were arguing about something in the news. 'I'd hate to live forever,' one of them said. She raised her voice. 'There's your change, love.' Kearney, who had been expecting to see his own name on page two of the paper, raised his head. She gave him a smile. 'Don't forget your change,' she said. He had found only the name of the woman he had killed in the Midlands; no one was looking for a Lancia Integrale. He folded the paper up and stared at a trickle of Asians making their way across the departure lounge for a flight to LAX. His phone chirped again. He took it out: voicemail.

'Hi,' said Brian Tate's voice. 'I've been trying to get you at horns.' He sounded irritable. 'I had an idea a couple of hours ago. Give me a ring if you get this.' There was a pause, and Kearney thought the message was over. Then Tate added, 'I'm really a bit concerned. Gordon was here again after you left. So call.' Kearney switched the phone off and stared at it. Behind Tate's voice he had heard the white cat mewing for attention.

'"Justine"!' he thought. It made him smile.

He sorted through the courier bag until he found the Shrander's dice. He held them in his hand. They always felt warm. The symbols on them appeared in no language or system of numbers he knew, historical or modern. On a pair of ordinary dice, each symbol would be duplicated; here, none was. Kearney watched them rattle across the tabletop and come to rest in the spilled coffee by his empty cup. He studied them for a moment, then scooped them up, stuffed newspaper and phone hastily into the courier bag, and left.

'Your change, love!'

The women looked after him, then at each other. One of them shrugged. By then, Kearney was in the lavatories, shivering and throwing up. When he came out, he found Anna waiting for him. Heathrow was awake now. People were hurrying to make flights, make phone calls, make headway. Anna stood fragile and listless in the middle of the concourse, staring every so often at their faces as they brushed past her. Every time she thought she saw him her face lit up. Kearney remembered her at Cambridge. Shortly after they met, a friend of hers had told him: 'We nearly lost her once. You will take care of her, won't you?' He had remained puzzled by this warning-with its image of Anna as a package that might easily slip the mind-only until he found her in the bathroom a month later, crying and staring ahead, with her wrists held out in front of her. Now she looked at him and said:

'I knew this is where you'd be.'

Kearney stared at her in disbelief. He began to laugh.

Anna laughed too. 'I knew you'd come here,' she said. 'I brought some of your things.'

'Anna -'

'You can't keep running away from it forever, you know.'

This made him laugh harder for a moment, then stop.

Kearney's adolescence had passed like a dream. When he wasn't in the fields, he was at the imaginary house he called Gorselands, with its stands of pine, sudden expanses of sandy heath, steep-sided valleys full of flowers and rocks. It was always full summer. He watched his cousins, leggy and elegant, walk naked down the beach at dawn; he heard them whisper in the attic. He was continually sore from masturbating. At Gorselands there was always more; there was always more after that. Inturned breathing, a sudden salty smell in an empty room. A murmur of surprise.

'All this dreaming gets you nowhere,' his mother said.

Everyone said that. But by now he had found numbers. He had seen how the same sequences underlay the structure of a galaxy and a spiral shell. Randomness and determination, chaos and emergent order: the new tools of physics and biology. Years before computer modelling made bad art out of the monster in the Mandelbrot Set, Kearney had seen it, churning and streaming and turbulent at the heart of things. Numbers made him concentrate more: they encouraged him to pay attention. Where he had winced away from school life, with its mixture of boredom and savagery, he now welcomed it. Without all that, the numbers made him see, he would not go to Cambridge, where he could begin to work with the real structures of the world.

He had found numbers. In his first year at Trinity someone showed him the Tarot.