On the second, his dream-self forsook the trudge across the wilderness and was delivered directly into the necropolis, his feet, easily tutored, following the same route as he had on his first visit. The constant wind was stronger tonight. It caught the lace curtains in this window, and a tinkling Chinese trinket hanging in that. It carried voices too; horrid and outlandish sounds that came from some distant place far beyond the city. Hearing that whirring and whittering, as of insane children, he was grateful for the streets and the rooms, for their familiarity if not for any comfort they might offer. He had no desire to step into those interiors, voices or no; did not want to discover what marked these snatches of architecture out that they should have been ripped from their roots and flung down in this whining desolation.

Yet, once he had visited the site, his sleeping mind went back there, night upon night; always walking, bloody-footed, seeing only the rats and the butterflies, and the black sand on each threshold, blowing into rooms and hallways that never changed from visit to visit; that seemed, from what he could glimpse between the curtains or through a shattered wall, to have been fixed somehow at some pivotal moment, with a meal left uneaten on a table set for three (the capon uncarved, the sauces steaming), or a shower left running in a bathroom in which the lamp perpetually swung; and in a room that might have been a lawyer's study a lap-dog, or else a wig torn off and flung to the floor, lying discarded on a fine carpet whose intricacies were half-devoured by sand.

Only once did he see another human being in the city: and that was Billy. It happened strangely. One night - as he dreamed the streets - he half-stirred from sleep. Billy was awake, and standing in the middle of the cell, staring up at the light through the window. It was not moonlight, but the boy bathed in it as if it were. His face was turned up to the window, mouth open and eyes closed. Cleve barely had time to register the trance the boy seemed to be in before the tranquillisers drew him back into his dream. He took a fragment of reality with him however, folding the boy into his sleeping vision. When he reached the city again, there was Billy Tait: standing on the street, his face turned up to the louring clouds, his mouth open, his eyes closed.

The image lingered a moment only. The next, the boy was away, his heels kicking up black fans of sand. Cleve called after him. Billy ran on however, heedless; and, with that inexplicable foreknowledge that dreams bring, Cleve knew where the boy was going. Off to the edge of the city, where the houses petered out and the desert began. Off to meet some friend coming in on that terrible wind, perhaps. Nothing would induce him into pursuit, yet he didn't want to lose contact with the one fellow human he had seen in these destitute streets. He called Billy's name again, more loudly.

This time he felt a hand on his arm, and started up in terror to find himself being jostled awake in his cell.

'It's all right,' Billy said. 'You're dreaming.'

Cleve tried to shake the city out of his head, but for several perilous seconds the dream bled into the waking world, and looking down at the boy he saw Billy's hair lifted by a wind that did not, could not, belong in the confines of the cell. 'You're dreaming,' Billy said again. 'Wake up.'

Shuddering, Cleve sat fully up on his bunk. The city was receding - was almost gone - but before he lost sight of it entirely he felt the indisputable conviction that Billy knew what he was waking Cleve from; that they had been there together for a few, fragile moments.

'You know, don't you?' he accused the pallid face at his side.

The boy looked bewildered. 'What are you talking about?'

Cleve shook his head. The suspicion became more incredible with each step he took from sleep. Even so, when he looked down at Billy's bony hand, which still clung to his arm, he half-expected to see flecks of that obsidian grit beneath his finger-nails. There was only dirt.

The doubts lingered however, long after reason should have bullied them into surrender. Cleve found himself watching the boy more closely from that night on, waiting for some slip of tongue or eye which would reveal the nature of his game. Such scrutiny was a lost cause. The last traces of accessibility disappeared after that night; the boy became - like Rosanna - an indecipherable book, letting no clue as to the nature of his secret world out from beneath his lids. As to the dream - it was not even mentioned again. The only roundabout allusion to that night was Billy's redoubled insistence that Cleve continue to take the sedatives.

'You need your sleep,' he said after coming back from the Infirmary with a further supply. 'Take them.'

'You need sleep too,' Cleve replied, curious to see how far the boy would push the issue. 'I don't need the stuff any more.'

'But you do,' Billy insisted, proffering the phial of capsules. 'You know how bad the noise is.'

'Someone said they're addictive,' Cleve replied, not taking the pills, 'I'll do without.'

'No,' said Billy; and now Cleve sensed a level of insistence which confirmed his deepest suspicions. The boy wanted him drugged, and had all along. 'I sleep like a babe,' Billy said. 'Please take them. They'll only be wasted otherwise.'

Cleve shrugged. 'If you're sure,' he said, content - fears confirmed - to make a show of relenting.

'I'm sure.'

Then thanks.' He took the phial.

Billy beamed. With that smile, in a sense, the bad times really began.

That night, Cleve answered the boy's performance with one of his own, appearing to take the tranquillisers as he usually did, but failing to swallow them. Once lying on his bunk, face to the wall, he slipped them from his mouth, and under his pillow. Then he pretended sleep.

Prison days both began and finished early; by 8.45 or 9.00 most of the cells in the four wings were in darkness, the inmates locked up until dawn and left to their own devices. Tonight was quieter than most. The weeper in the next cell but one had been transferred to D Wing; there were few other disturbances along the landing. Even without the pill Cleve felt sleep tempting him. From the bunk below he heard practically no sound, except for the occasional sigh. It was impossible to guess if Billy was actually asleep or not. Cleve kept his silence, occasionally stealing a moment-long glance at the luminous face of his watch. The minutes were leaden, and he feared, as the first hours crept by, that all too soon his imitation of sleep would become the real thing. Indeed he was turning this very possibility around in his mind when unconsciousness overcame him.

He woke much later. His sleep-position seemed not to have altered. The wall was in front of him, the peeled paint like a dim map of some nameless territory. It took him a minute or two to orient himself. There was no sound from the bunk below. Disguising the gesture as one made in sleep, he drew his arm up within eye-range, and looked at the pale-green dial of his watch. It was one-fifty-one. Several hours yet until dawn. He lay in the position he'd woken in for a full quarter of an hour, listening for every sound in the cell, trying to locate Billy. He was loathe to roll over and look for himself, for fear that the boy was standing in the middle of the cell as he had been the night of the visit to the city.

The world, though benighted, was far from silent. He could hear dull footsteps as somebody paced back and forth in the corresponding cell on the landing above; could hear water rushing in the pipes and the sound of a siren on the Caledonian Road. What he couldn't hear was Billy. Not a breath of the boy.

Another quarter of an hour passed, and Cleve could feel the familiar torpor closing in to reclaim him; if he lay still much longer he would fall asleep again, and the next thing he'd know it would be morning. If he was going to learn anything, he had to roll over and look. Wisest, he decided, not to attempt to move surreptitiously, but to turn over as naturally as possible. This he did, muttering to himself, as if in sleep, to add weight to the illusion. Once he had turned completely, and positioned his hand beside his face to shield his spying, he cautiously opened his eyes.