I think he was trying to laugh, at this point, or the laugh was just coming naturally because of his macabre sense of humour, I'm not sure; whatever it was it ended in more coughing, because of the cigarette smoke. I suppose his lungs were in a pretty bad way, with the ashtrays always full.

'Then,' he said when he could, 'you'd wind him up and he'd move the wooden stick up and down, beating the bare feet of the doll who's hanging upside down from the trapeze. I'm sure,' he said and the laughter started now, and I hope I never hear a sound like that again, 'I'm sure all the little boys would tug their mummies along there to buy one — in this country it'd be a smash hit, don't you think?'

The laughter went on, the strangest sound I have ever heard from a human throat, a kind of soft yelping, like the cry of an animal caught in a trap. I saw Misha staring at him, her plump hands going slowly to her face, while Ignatov watched him with his thick grey mouth slightly open, his eyes bewildered.

Schrenk stood in a crouch as the breath came out of his body in spasms; his eyes were squeezed almost shut, with the glint of tears showing. 'You see,' he said painfully, 'I finally succeeded in making a connection, a connection between Children's World and that other world across the square. I could finally believe they existed within a stone's throw of each other. Of course there's always the funny side to these things, isn't there, I mean quite a lot of good citizens are taken inside Lubyanka for interrogation, sometimes for days on end if they prove obstinate, as you well know.' Ash dropped from his cigarette and he brushed it clumsily off his jacket. 'So you can easily imagine a young mother, worried about the fact that her Jewish husband has disappeared, buying her little boy the funny mechanical toy he's been pestering her for. Then, when he keeps on asking where Daddy is, she can tell him not to worry about him, just go and play with his toy.' He began laughing again, in soft little yelps. 'Don't you think that's an absolute — absolute scream?' But when he swung his head up to look at me I saw the hatred burning in his eyes with a white hot flame.

Then I understood. His rage wasn't against me. It was against that jackbooted crowd of thugs in Lubyanka, and the regime in which they operated, and the order of command that structured it from the omnipotent Politburo down to the cocky little militia men in the streets. Dr Steinberg had been surprised that I hadn't grasped that most obvious of facts: that when you damage a man as they had damaged Schrenk, with your bare hands and with special implements and with humiliation, you will engender in what remains of him the most murderous hate. It does, after all, become personal.

I could believe him now. Schrenk wasn't a defector.

Misha had got him to sit down again on the settee, and for a moment sat with him, her head against his shoulder and her hand cupping his cheek. She looked at me with her face questioning, then withdrew into herself as she remembered what I had done to Ignatov.

'Work for them?' Schrenk said bitterly. He shook off the girl and stared at me.

'What does he say?' she pleaded to Ignatov. 'What is it about, this Lubyanka and this Detsky Mir?'

'I don't know,' he said broodingly.

'Why did the man hit you like that? Should I get the police?'

'You know better,' he said, 'than to get the police.'

Schrenk patted the girl's hand. 'There's nothing to worry about, sweetheart. But your Viktor would like some tea. Would you make some tea for us?'

'There's some in the samovar,' she said eagerly, sensing a return to normal.

'That would be very nice.'

She hugged him in relief and I saw pain flicker across his face; then she bounced off the settee and ran across to the urn, leaving him staring at me.

'We've got a mission on the board,' I said, 'and I'm the executive in the field. Guess what they want me to do.'

He brushed ash off his knees. 'Tell them I'll make my report when I'm ready. I'm not ready yet.'

'The objective,' I said patiently, 'is to get you out of Russia.'

'Sorry I can't help you.' He drained his glass of vodka and put it on to the rickety little stool at the end of the settee, getting it wrong and letting it fall to the carpet. Ignatov ambled forward to pick it up for him.

'Leave it there.'

'Of course, Viktor.'

'I can pick things up for myself, don't you know that?'

'I was forgetting.'

We watched Schrenk double over and feel for the glass, his hand swinging like a hook till his fingers connected with the rim; then he put the glass back on to the stool with ostentatious care, though it rattled to the trembling of his hand before he could stop it.

'You mean,' I asked him, 'you're staying in Moscow?'

'I've got friends here.'

'If they're anything like this son of a bitch here then you're welcome to them.'

He laughed and said: 'He's not too fond of you either. Why do they want me out of Russia?'

'They want to debrief you on the interrogation.' I could tell him so much and no more. He was going to lie when it suited him and he was going to do it convincingly, and if I shot questions at him I was going to get as much out of him as they'd got out of him in Lubyanka. All I could do was feel my way softly into the rage, into the silently roaring battlefield they'd made of his mind, and hope to intercept a few signals when he was off his guard, and try to come out alive and get the message to Bracken. 'They want to give you some leave. You've earned that, God knows.'

'I'll pay my own way,' he said, and fumbled in the black and yellow packet for another cigarette.

It meant nothing at all. It was just a spark coming out of the volcano. I had to find a way of reaching him. 'Natalya hopes to see you again.' At the edge of my vision field I saw Misha turn her head to listen.

'Natalya's dangerous,' Schrenk said at once. 'Don't forget that.' He didn't ask me how I'd got on to her: he knew that when I'd come into the field I would have started by contacting his friends.

'Noted,' I said. 'But she's got her heart in the right place. They're all worried about Borodinski.' It was an oblique shot and I got a hit though he kept most of his control.

'Certainly they're worried about Borodinski.'

'D'you think he'll get off?'

'Get off?' No control now. 'He'll get life, you know that.'

I took it further. 'There's a lot of protests going on.'

'Protests? They're not protests, for God's sake! There's only one thing those bastards'll listen to.' Then he angled his head and watched me steadily. 'You're not interested in Borodinski.'

No go.

Ignatov moved and I whipped a glance at him, but he was only helping the girl with the tray of tea. The room was full of comfortable sounds: the clinking of cups on saucers and the slow tick of the clock. But the company was wrong. Give Schrenk a few more days in here and he'd wire himself to that clock and blow the whole building apart.

'Thank you, sweetheart,' he said, and took his cup from her. 'The thing is,' his head turning to me, 'I want to be left alone for a bit. I've done enough for London, for the moment, you've said that yourself. I applied for a job here as an a-i-p but you know what happens to an application in that bloody place, it's like a snake trying to scratch its arse, can never quite find it.' He sipped some tea. 'So you see I don't want anyone coming here, you or Bracken or anyone else. And that makes it difficult, doesn't it?' He didn't look at me when he said that. He wasn't going to enjoy this, and neither was I, but it was something we had to do, had to work out.

Misha brought some tea for me, standing directly between Schrenk and me with her plump country-girl's body and whispering, 'Who is Natalya?'