How long was it since he'd approached a lime-green bath in a lime-green bathroom, and peered into the water? It could have been yesterday: his life between then and now had become one long night. He looked down. It was there, tucked up, as before, and asleep, still wearing all its clothes as though it had had no time to undress before it hid itself. Where it had been bald it now sprouted a luxuriant head of hair, and its features were quite complete. No trace of a painted face remained: it had a plastic beauty that was his own absolutely, down to the last mole. Its perfectly finished hands were crossed on its chest.

The night deepened. There was nothing to do but watch it sleep, and he became bored with that. It had traced him here, it wasn't likely to run away again, he could go back to bed. Outside the rain had slowed the commuters' homeward journey to a crawl, there were accidents, some fatal; engines overheated, hearts too. He listened to the chase; sleep came and went. It was the middle of the evening when thirst woke him again: he was dreaming water, and there was the sound as it had been before. The creature was hauling itself out of the bath, was putting its hand to the door, opening it.

There it stood. The only light in the bedroom was coming from the street below; it barely began to illuminate the visitor.

'Gavin? Are you awake?'

'Yes,' he said.

'Will you help me?' it asked. There was no trace of threat in its voice, it asked as a man might ask his brother, for kinship's sake.

'What do you want?'

'Time to heal.'

'Heal?'

'Put on the light.'

Gavin switched on the lamp beside the bed and looked at the figure at the door. It no longer had its arms crossed on its chest, and Gavin saw that the position had been covering an appalling shotgun wound. The flesh of its chest had been blown open, exposing its colourless innards. There was, of course, no blood: that it would never have. Nor, from this distance, could Gavin see anything in its interior that faintly resembled human anatomy.

'God Almighty,' he said.

'Preetorius had friends,' said the other, and its ringers touched the edge of the wound. The gesture recalled a-picture of the wall of his mother's house. Christ in Glory - the Sacred Heart floating inside the Saviour - while his fingers, pointing to the agony he'd suffered, said: This was for you.'

'Why aren't you dead?'

'Because I'm not yet alive,' it said.

Not yet: remember that, Gavin thought. It has intimations of mortality.

'Are you in pain?'

'No,' it said sadly, as though it craved the experience, 'I feel nothing. All the signs of life are cosmetic. But I'm learning.' It smiled. 'I've got the knack of the yawn, and the fart.' The idea was both absurd and touching; that it would aspire to farting, that a farcical failure in the digestive system was for it a precious sign of humanity.

'And the wound?'

' - is healing. Will heal completely in time.'

Gavin said nothing.

'Do I disgust you?' it asked, without inflection.

'No.'

It was staring at Gavin with perfect eyes, his perfect eyes.

'What did Reynolds tell you?' it asked.

Gavin shrugged.

'Very little.'

That I'm a monster? That I suck out the human spirit?'

'Not exactly.'

'More or less.'

'More or less,' Gavin conceded.

It nodded. 'He's right,' it said. 'In his way, he's right. I need blood: that makes me monstrous. In my youth, a month ago, I bathed in it. Its touch gave wood the appearance of flesh. But I don't need it now: the process is almost finished. All I need now…

It faltered; not, Gavin thought, because it intended to lie, but because the words to describe its condition wouldn't come.

'What do you need?' Gavin pressed it.

It shook its head, looking down at the carpet. 'I've lived several times, you know. Sometimes I've stolen lives and got away with it. Lived a natural span, then shrugged off that face and found another. Sometimes, like the last time, I've been challenged, and lost - '

'Are you some kind of machine?'

'No.'

'What then?'

'I am what I am. I know of no others like me; though why should I be the only one? Perhaps there are others, many others: I simply don't know of them yet. So I live and die and live again, and learn nothing - ' the word was bitterly pronounced, ' - of myself. Understand? You know what you are because you see others like you. If you were alone on earth, what would you know? What the mirror told you, that's all. The rest would be myth and conjecture.'

The summary was made without sentiment.

'May I lie down?' it asked.

It began to walk towards him, and Gavin could see more clearly the fluttering in its chest-cavity, the restless, incoherent forms that were mushrooming there in place of the heart. Signing, it sank face-down on the bed, its clothes sodden, and closed its eyes.

'We'll heal,' it said. 'Just give us time.'

Gavin went to the door of the flat and bolted it. Then he dragged a table over and wedged it under the handle. Nobody could get in and attack it in sleep: they would stay here together in safety, he and it, he and himself. The fortress secured, he brewed some coffee and sat in the chair across the room from the bed and watched the creature sleep.

The rain rushed against the window heavily one hour, lightly the next. Wind threw sodden leaves against the glass and they clung there like inquisitive moths; he watched them sometimes, when he tired of watching himself, but before long he'd want to look again, and he'd be back staring at the casual beauty of his outstretched arm, the light flicking the wrist-bone, the lashes. He fell asleep in the chair about midnight, with an ambulance complaining in the street outside, and the rain coming again.

It wasn't comfortable in the chair, and he'd surface from sleep every few minutes, his eyes opening a fraction. The creature was up: it was standing by the window, now in front of the mirror, now in the kitchen. Water ran: he dreamt water. The creature undressed: he dreamt sex. It stood over him, its chest whole, and he was reassured by its presence: he dreamt, it was for a moment only, himself lifted out of a street through a window into Heaven. It dressed in his clothes: he murmured his assent to the theft in his sleep. It was whistling: and there was a threat of day through the window, but he was too dozy to stir just yet, and quite content to have the whistling young man in his clothes live for him.

At last it leaned over the chair and kissed him on the lips, a brother's kiss, and left. He heard the door close behind it.

After that there were days, he wasn't sure how many, when he stayed in the room, and did nothing but drink water. This thirst had become unquenchable. Drinking and sleeping, drinking and sleeping, twin moons.

The bed he slept on was damp at the beginning from where the creature had laid, and he had no wish to change the sheets. On the contrary he enjoyed the wet linen, which his body dried out too soon. When it did he took a bath himself in the water the thing had lain in and returned to the bed dripping wet, his skin crawling with cold, and the scent of mildew all around. Later, too indifferent to move, he allowed his bladder free rein while he lay on the bed, and that water in time became cold, until he dried it with his dwindling body-heat.

But for some reason, despite the icy room, his nakedness, his hunger, he couldn't die.

He got up in the middle of the night of the sixth or seventh day, and sat on the edge of the bed to find the flaw in his resolve. When the solution didn't come he began to shamble around the room much as the creature had a week earlier, standing in front of the mirror to survey his pitifully changed body, watching the snow shimmer down and melt on the sill.