The cell seemed darker than it had the night he had seen Billy with his face up to the window. As to the boy, he was not visible. Cleve opened his eyes a little wider and scanned the cell as best he could from between his fingers. There was something amiss, but he couldn't quite work out what it was. He lay there for several minutes, waiting for his eyes to become accustomed to the murk. They didn't. The scene in front of him remained unclear, like a painting so encrusted with dirt and varnish its depths refuse the investigating eye. Yet he knew - knew - that the shadows in the corners of the cell, and on the opposite wall, were not empty. He wanted to end the anticipation that was making his heart thump, wanted to raise his head from the pebble-filled pillow and call Billy out of hiding. But good sense counselled otherwise. Instead he lay still, and sweated, and watched.

And now he began to realize what was wrong with the scene before him. The concealing shadows fell where no shadows belonged; they spread across the hall where the feeble light from the window should have been falling. Somehow, between window and wall, that light had been choked and devoured. Cleve closed his eyes to give his befuddled mind a chance to rationalize and reject this conclusion. When he opened them again his heart lurched. The shadow, far from losing potency, had grown a little.

He had never been afraid like this before; never felt a coldness in his innards akin to the chill that found him now. It was all he could do to keep his breath even, and his hands where they lay. His instinct was to wrap himself up and hide his face like a child. Two thoughts kept him from doing so. One was that the slightest movement might draw unwelcome attention to him. The other, that Billy was somewhere in the cell, and perhaps as threatened by this living darkness as he.

And then, from the bunk below, the boy spoke. His voice was soft, so as not to wake his sleeping cell-mate presumably. It was also eerily intimate. Cleve entertained no thought that Billy was talking in his sleep; the time for wilful self-deception was long past. The boy was addressing the darkness; of that unpalatable fact there could be no doubt.

'... it hurts ...' he said, with a faint note of accusation,'... you didn't tell me how much it hurts ...'

Was it Cleve's imagination, or did the wraith of shadows bloom a little in response, like a squid's ink in water? He was horribly afraid. The boy was speaking again. His voice was so low Cleve could barely catch the words.

'... it must be soon ...' he said, with quiet urgency, '... I'm not afraid. Not afraid.'

Again, the shadow shifted. This time, when Cleve looked into its heart, he made some sense of the chimerical form it embraced. His throat shook; a cry lodged behind his tongue, hot to be shouted.

'... all you can teach me ...' Billy was saying,'... quickly ...' The words came and went; but Cleve barely heard them. His attention was on the curtain of shadow, and the figure - stitched from darkness - that moved in its folds. It was not an illusion. There was a man there: or rather a crude copy of one, its substance tenuous, its outline deteriorating all the time, and being hauled back into some semblance of humanity again only with the greatest effort. Of the visitor's features Cleve could see little, but enough to sense deformities paraded like virtues: a face resembling a plate of rotted fruit, pulpy and peeling, swelling here with a nest of flies, and there suddenly fallen away to a pestilent core. How could the boy bring himself to converse so easily with such a thing? And yet, putresence notwithstanding, there was a bitter dignity in the bearing of the creature, in the anguish of its eyes, and the toothless O of its maw.

Suddenly, Billy stood up. The abrupt movement, after so many hushed words, almost unleashed the cry from Cleve's throat. He swallowed it, with difficulty, and closed his eyes down to a slit, staring through the bars of his lashes at what happened next.

Billy was talking again, but now the voice was too low to allow for eavesdropping. He stepped towards the shadow, his body blocking much of the figure on the opposite wall. The cell was no more than two or three strides wide, but, by some mellowing of physics, the boy seemed to take five, six, seven steps away from the bunk. Cleve's eyes widened: he knew he was not being watched. The shadow and its acolyte had business between them: it occupied their attention utterly.

Billy's figure was smaller than seemed possible within the confines of the cell, as if he had stepped through the wall and into some other province. And only now, with his eyes wide, did Cleve recognize that place. The darkness from which Billy's visitor was made was cloud-shadow and dust; behind him, barely visible in the bewitched murk, but recognizable to any who had been there, was the city of Cleve's dreams.

Billy had reached his master. The creature towered above him, tattered and spindly, but aching with power. Cleve didn't know how or why the boy had gone to it, and he feared for Billy's safety now that he had, but fear for his own safety shackled him to the bunk. He realized in that moment that he had never loved anyone, man or woman, sufficiently to pursue them into the shadow of that shadow. The thought brought a terrible sense of isolation, knowing that same instant that none, seeing him walk to his damnation, would take a single step to claim him from the brink. Lost souls both; he and the boy.

Now Billy's lord was lifting his swollen head, and the incessant wind in those blue streets was rousing his horse-mane into furious life. On the wind, the same voices Cleve had heard carried before, the cries of mad children, somewhere between tears and howls. As if encouraged by these voices, the entity reached out towards Billy and embraced him, wrapping the boy round in vapour. Billy did not struggle in this embrace, but rather returned it. Cleve, unable to watch this horrid intimacy, closed his eyes against it, and when -seconds? minutes?, later - he opened them again, the encounter seemed to be over. The shadow-thing was blowing apart, relinquishing its slender claim to coherence. It fragmented, pieces of its tattered anatomy flying off into the streets like litter before wind. Its departure seemed to signal the dispersal of the entire scene; the streets and houses were already being devoured by dust and distance. Even before the last of the shadow's scraps had been wafted out of sight the city was lost to sight. Cleve was pleased to be shut of it. Reality, grim as it was, was preferable to that desolation. Brick by painted brick the wall was asserting itself again, and Billy, delivered from his master's arms, was back in the solid geometry of the cell, staring up at the light through the window.

Cleve did not sleep again that night. Indeed he wondered, lying on his unyielding mattress and staring up at the stalactites of paint depending from the ceiling, whether he could ever find safety in sleep again.

Sunlight was a showman. It threw its brightness down with such flamboyance, eager as any tinsel-merchant to dazzle and distract. But beneath the gleaming surface it illuminated was another state; one that sunlight - ever the crowd-pleaser - conspired to conceal. It was vile and desperate, that condition. Most, blinded by sight, never even glimpsed it. But Cleve knew the state of sunlessness now; had even walked it, in dreams; and though he mourned the loss of his innocence, he knew he could never retrace his steps back into light's hall of mirrors.

He tried his damnedest to keep this change in him from Billy; the last thing he wanted was for the boy to suspect his eavesdropping. But concealment was well-nigh impossible. Though the following day Cleve made every show of normality he could contrive, he could not quite cover his unease. It slipped out without his being able to control it, like sweat from his pores. And the boy knew, no doubt of it, he knew. Nor was he slow to give voice to his suspicions. When, following the afternoon's Workshop, they returned to their cell, Billy was quick to come to the point.