'He told them,' he said at last, 'that you were Helmut Schrenk.' He tried to laugh but it turned into a coughing fit and he bent over, drawing in smoke with the air and making it worse until the girl went over to him and held his thin shaking body.

I should have thought of that. I should have realized why they'd come at me so fast and with so many men, and why Colonel Vader had been so annoyed when he'd realized I wasn't Schrenk.

'I had to get you out of the way,' he said between the spasms of coughing. 'I had to get you locked up, so that you couldn't — ' he broke off, interrupted by a fresh paroxysm, and lost his train of thought. 'But it obviously didn't work.'

'Yes,' I said, 'it worked.'

He turned to face me at last, his eyes bloodshot and the cigarette trembling in his hand and his body twisted with the effort of keeping upright.

`What happened?'

`They took me into Lubyanka.'

He went on staring at me. 'You were lucky. Is that all they did to you?' He meant my face.

Ignatov was moving.

'What is it you've got to do,' I asked Schrenk, 'that needs me out of the way? And how much is the KGB going to pay you?'

The colour was leaving his face. In something like a whisper he said, 'You think I'd work for them?'

'If you could do what you did to me, you could do anything.'

He crumpled as if I'd hit him. His head went down and his eyes clenched shut and he stood there sagging like a puppet under invisible wires and for a moment I felt the sweetness of revenge coming into me and warming me, and then, when it was over, I was able to think more clearly and remember that this wasn't Schrenk at all; it was the remains of the man they had worked on in Lubyanka.

'Help him to sit down,' I said in Russian to the girl.

Ignatov moved again.

It seemed a long time before Schrenk was on the settee, looking up at me, dragging on the new cigarette Misha had lit for him. 'You think I'd work for them?'

`You don't seem to be working for us any more.'

'I suppose,' he said and dragged more smoke in, hungry for it, 'I suppose you think I blew Leningrad, do you?'

'No. It's still intact.'

`That doesn't tell you anything?'

Ignatov moved again and this time vanished behind my field of vision. He was working his way towards the door, behind me. I got very annoyed and swung round with a face-high back-hammer fist and he hit the door with a crash and bounced off and brought down a stack of shelves with cheap ornaments on them and I watched them disintegrating on the threadbare carpet while the girl screamed. Ignatov was staring up at me, blood trickling on his temple.

`Don't you ever listen?' I asked him.

It was very quiet. There didn't seem to be any noise in the whole of the building. Bad security: I hadn't got any more control than Schrenk.

Misha was hurrying across to help Ignatov, her face shocked as she passed me. One of those coy little Hummel figurines with gold paint on it and its toes turned in toppled off the remains of the shelves and broke on the floor, so I hadn't chalked up a total failure.

'What did he do?' Schrenk asked me irritably.

'Tell him if he tries to leave this room I'm going to kill him. He won't listen to me.'

'Pyotr,' Schrenk said in Russian, 'keep away from the door. And clear up that mess.' Then he looked at me again and said in soft astonishment, 'Work for them?' Apparently it had been on his mind.

'Oh come on,' I said impatiently, 'it's happened before.'

He looked shocked. 'Not anyone from our show.'

'There's a first time for everything.'

Then he was on his feet again, moving very fast considering his condition. 'I tell you I'm not a defector!'

The veins were standing out on his temples and he was staring at me with the last control over his rage slipping away. 'Do you understand that?'

In a moment I said: 'I don't understand anything, yet. I was hoping you could help me.'

Misha went over to him and tried to make him sit down again but he didn't even know she was there: he just went on staring at me, his thin body trembling. 'Detsky Mir,' he said softly, 'Detsky Mir,' with his mouth twisting into a hateful smile. Ignatov was looking up at him, his hands full of broken china, and the girl's face had gone blank. I didn't know what Schrenk was talking about either: Detsky Mir was a big shopping centre, that was all — Children's World.

No one spoke. I listened to the slow tick of the clock in the corner, and the sounds that had come into the building again. I'd been expecting someone along here knocking on the door because Ignatov had made a lot of noise with the china and Misha had screamed, but nobody came. Family fight.

Schrenk was getting over his rage, but there was something else there just as intense. He stayed on his feet, and he brought the words out with the whole of his body, twisting and crouching over them as if he were whittling them away, one by one, with a razor-sharp knife. His eyes never left my face. 'I had time, inside Lubyanka, to think about Children's World. All those soft cuddly animals, and toy trains, and ribbons for little girls. I had a lot of time.'

I was beginning to pick up a thread. Children's World is right opposite Lubyanka, in Dzerzhinsky Square. In Lubyanka there are no windows along the top floor, because the top floor is only a facade bordering an open space under the sky, with a machine-gun positioned in each corner: it is the exercise yard for the prison. I'd passed Children's World on my way to the prison when they'd picked me up in Red Square.

'I spent a lot of my time,' Schrenk said, whittling the words out, 'trying to see some connection. Some connection between those two places. I had more time in there, you see, than you did, and you've got to think of something, haven't you, when they start work.'

Schrenk prided himself on his ability to survive the most gruelling interrogation by the use of practised and convincing disinformation, Croder had said. We tested him at Norfolk, and even hypnosis couldn't break him down. That is the sort of man he is. But we don't know how bad the position is, because we don't know how much he gave away.

Nothing. He'd given away nothing. Not even Leningrad, let alone London. Now he was here in this squalid little room, staring at me, wanting me to know something important, his maimed body trembling with the remnants of his rage and with something else I didn't understand. That was why I was listening carefully.

'And finally I got it,' he said, 'I got a connection going between Children's World and Lubyanka. It worried me, you see. I mean, it's like having one of our prisons with its execution chamber right across the street from Harrods. Could only happen in Moscow, couldn't it? Typically Russian — slightly short on good taste.' He got himself a cigarette before Misha could do it for him, and flicked the match away. 'I had to think up a connection, yes. Wandering a bit, am I?'

'No.'

Ignatov had finished clearing up and was squatting on a tea chest near the grandfather clock, watching Schrenk, not understanding a word but listening to the sharp dry sibilants that cut through the silence.

'They're so clever these days, aren't they, at making mechanical toys. I mean that monkey, you know, that beats the two little brass cymbals together when you wind it up — that's old hat now, but I'm not thinking of anything more complicated. Surely they could make a small doll, with trousers and a moustache to show he's a man, and hang him upside down from a kind of trapeze with another doll beside him, also in trousers and with bushy black eyebrows slanting down towards the middle to make him look fierce, and a wooden stick in his hand — you see what I mean? It shouldn't be too difficult.'