The girl had led him into a cul-de-sac; she herself had disappeared however, leaving him facing a plain brick wall, much weathered, with a narrow window in it. He approached: this was clearly what he'd been led here to see. He peered through the reinforced glass, dirtied on his side by an accumulation of bird-droppings, and found himself staring into one of the cells at Pentonville. His stomach flipped over. What kind of game was this; led out of a cell and into this dream-city, only to be led back into prison? But a few seconds of study told him that it was not his cell. It was Lowell and Nayler's. Theirs were the pictures sellotaped to the grey brick, theirs the blood spread over floor and wall and bunk and door. This was another murder-scene.

'My God Almighty,' he murmured. 'Billy ...'

He turned away from the wall. In the sand at his feet lizards were mating; the wind that found its way into this backwater brought butterflies. As he watched them dance, the bell rang in B Wing, and it was morning.

It was a trap. Its mechanism was by no means clear to Cleve - but he had no doubt of its purpose. Billy would go to the city; soon. The cell in which he had committed murder already awaited him, and of all the wretched places Cleve had seen in that assemblage of charnel-houses surely the tiny, blood-drenched cell was the worst.

The boy could not know what was planned for him; his grandfather had lied about the city by exclusion, failing to tell Billy what special qualifications were required to exist there. And why? Cleve returned to the oblique conversation he'd had with the man in the kitchen. That talk of exchanges, of deal-making, of going back. Edgar Tait had regretted his sins, hadn't he?; he'd decided, as the years passed, that he was not the Devil's excrement, that to be returned into the world would not be so bad an idea. Billy was somehow an instrument in that return.

'My grandfather doesn't like you,' the boy said, when they were locked up again after lunch. For the second consecutive day all recreation and workshop activities had been cancelled, while a cell-by-cell enquiry was undertaken regarding Lowell, and - as of the early hours of that day - Nayler's deaths.

'Does he not?' Cleve said. 'And why?'

'Says you're too inquisitive. In the city.'

Cleve was sitting on the top bunk; Billy on the chair against the opposite wall. The boy's eyes were bloodshot; a small, but constant, tremor had taken over his body.

'You're going to die,' Cleve said. What other way to state that fact was there, but baldly? 'I saw ... in the city ...'

Billy shook his head. 'Sometimes you talk like a crazyman. My grandfather says I shouldn't trust you.'

'He's afraid of me, that's why.'

Billy laughed derisively. It was an ugly sound, learned, Cleve guessed, from Grandfather Tait. 'He's afraid of no-one,' Billy retorted.

' - afraid of what I'll see. Of what I'll tell you.'

'No,' said the boy, with absolute conviction.

'He told you to kill Lowell, didn't he?'

Billy's head jerked up. 'Why'd you say that?'

'You never wanted to murder him. Maybe scare them both a bit; but not kill them. It was your loving grandfather's idea.'

'Nobody tells me what to do,' Billy replied; his gaze was icy. 'Nobody.'

'All right,' Cleve conceded, 'maybe he persuaded you, eh?; told you it was a matter of family pride. Something like that?' The observation clearly touched a nerve; the tremors had increased.

'So? What if he did?'

'I've seen where you're going to go, Billy. A place just waiting for you ...' The boy stared at Cleve, but didn't make to interrupt. 'Only murderers occupy the city, Billy. That's why your grandfather's there. And if he can find a replacement - if he can reach out and make more murder - he can go free.'

Billy stood up, face like a fury. All trace of derision had gone. 'What do you mean: free?'

'Back to the world. Back here.'

'You're lying -'

'Ask him.'

'He wouldn't cheat me. His blood's my blood.'

'You think he cares? After fifty years in that place, waiting for a chance to be out and away. You think he gives a damn how he does it?'

'I'll tell him how you lie...' Billy said. The anger was not entirely directed at Cleve; there was an undercurrent of doubt there, which Billy was trying to suppress. 'You're dead,' he said, 'when he finds out how you're trying to poison me against him. You'll see him, then. Oh yes. You'll see him. And you'll wish to Christ you hadn't.'

There seemed to be no way out. Even if Cleve could convince the authorities to move him before night fell - (a slim chance indeed; he would have to reverse all that he had claimed about the boy - tell them Billy was dangerously insane, or something similar. Certainly not the truth.) - even if he were to have himself transferred to another cell, there was no promise of safety in such a manoeuvre. The boy had said he was smoke and shadow. Neither door nor bars could keep such insinuations at bay; the fate of Lowell and Nayler was proof positive of that. Nor was Billy alone. There was Edgar St Clair Tait to be accounted for; and what powers might he possess? Yet to stay in the same cell with the boy tonight would amount to self-slaughter, wouldn't it? He would be delivering himself into the hands of the beasts.

When they left their cells for the evening meal, Cleve looked around for Devlin, located him, and asked for the opportunity of a short interview, which was granted. After the meal, Cleve reported to the officer.

'You asked me to keep an eye on Billy Tait, sir.'

'What about him?'

Cleve had thought hard about what he might tell Devlin that would bring an immediate transfer: nothing had come to mind. He stumbled, hoping for inspiration, but was empty-mouthed.

'I... I... want to put in a request for a cell transfer.'

'Why?'

The boy's unbalanced,' Cleve replied. 'I'm afraid he's going to do me harm. Have another of his fits -'

'You could lay him flat with one hand tied behind your back; he's worn to the bone.' At this point, had he been talking to Mayflower, Cleve might have been able to make a direct appeal to the man. With Devlin such tactics would be doomed from the beginning.

'I don't know why you're complaining. He's been as good as gold,' said Devlin, savouring the parody of fond father. 'Quiet; always polite. He's no danger to you or anyone.'

'You don't know him -'

'What are you trying to pull here?'

Put me in a Rule 43 cell, sir. Anywhere, I don't mind. Just get me out of his way. Please.'

Devlin didn't reply, but stared at Cleve, mystified. At last, he said, 'You are scared of him.'

'Yes.'

'What's wrong with you? You've shared cells with hard men and never turned a hair.'

'He's different,' Cleve replied; there was little else he could say, except: 'He's insane. I tell you he's insane.'

'All the world's crazy, save thee and me, Smith. Hadn't you heard?' Devlin laughed. 'Go back to your cell and stop belly-aching. You don't want a ghost train ride, now do you?'

When Cleve returned to the cell, Billy was writing a letter. Sitting on his bunk, poring over the paper, he looked utterly vulnerable. What Devlin had said was true: the boy was worn to the bone. It was difficult to believe, looking at the ladder of his vertebrae, visible through his T-shirt, that this frail form could survive the throes of transformation. But then, maybe it would not. Maybe the rigours of change would tear him apart with time. But not soon enough.

'Billy ...'

The boy didn't take his eyes from his letter.

'... what I said, about the city ...'

He stopped writing -

'... maybe I was imagining it all. Just dreaming ...'

- and started again.

'... I only told you because I was afraid for you. That was all. I want us to be friends ...'