'I'm afraid not,' I said. 'I used to take lessons but they somehow never made much difference.'

'Marvellous courses but they made us hire bloody Noddy carts. Wouldn't be seen dead in the things over here.' He drank again, the same slow ritual. 'Wintle's an oddball,' he explained when he had swallowed. 'They're all oddballs but Wintle's got odder balls than most. He's done Socialism, he's done Jesus. Now he's into contemplation and Tai Chi. Married, thank God. Grammar school but talks proper. Three years to go.'

'How much have you told him?' Ned asked.

'They always think they're under suspicion. I've told him he isn't, and I've told him to keep his stupid mouth shut when it's over.'

'And do you think he will?' I asked.

O'Mara shook his head. 'Don't know how to, most of 'em, however hard we boot 'em.'

There was a knock at the door and Wintle came in, an eternal student of fifty-seven. He was tall but crooked, with a curly grey head that shot off at an angle, and an air of brilliance almost extinguished. He wore a sleeveless Fair Isle pullover, Oxford bags and moccasins. He sat with his knees together and held his sherry glass away from him like a chemical retort he wasn't sure of.

Ned had turned professional. His tantrums were set aside. 'We're in the business of tracking Soviet scientists,' he said, managing to make himself sound dull. 'Watching the snakes and ladders of their defence establishment. Nothing very sexy, I'm afraid.'

'So you're Intelligence,' said Wintle. 'I thought as much, though I didn't say anything.'

It occurred to me that he was a very lonely man.

'Mind your own fucking business what they are,' O'Mara advised him perfectly pleasantly. 'They're English and they've got a job to do, same as you.'

Ned fished a couple of typed sheets from a folder and handed them to Wintle, who put down his glass to take them. His hands had a way of finishing knuckles down and fingers curled, like a man begging to be freed.

'We're trying to maximalise some of our neglected old material,' Ned said, falling into a jargon he would otherwise have eschewed. 'This is an account of your debriefing when you returned from a visit to Akademgorodok in August, 1963. Do you remember a Major Vauxhall? It's not exactly a literary masterpiece but you mention the names of two or three Soviet scientists we'd be grateful to catch up with, if they're still around and you remember them.'

As if to protect himself from a gas attack, Wintle pulled on a pair of extraordinarily ugly steel-framed spectacles.

'As I recall that debriefing, Major Vauxhall gave me his word of honour that everything I said was entirely voluntary and confidential,' he declared with a didactic jerkiness. 'I am therefore very surprised to see my name and my words lying about in open Ministerial archives a full twenty-five years after the event.'

'Well it's the nearest you'll ever get to immortality, sport, so I should shut up and enjoy it,' O'Mara advised.

I interposed myself like somebody separating belligerents in a family row. If Wintle could just expand a little on the interviewer's rather bald account, I suggested. Maybe flesh out one or two of the Soviet scientists whose names are listed on the final page, and perhaps throw in some account of the Cambridge team while he was about it? If he wouldn't mind answering just one or two questions which might tilt the scales?

'"Team" is not a word I would use in this context, thank you,' Wintle retorted, pouncing on the word like some bony predator. 'Not on the British side anyway. Team suggests common purpose. We were a Cambridge group , yes. A team , no. Some went for the ride, some went for the self-aggrandisement. I refer particularly to Professor Callow who had a highly exaggerated opinion of his work on accelerators, since refuted.' His Birmingham accent had escaped from its confinement. 'A very small minority indeed had ideological motives. They happened to believe in science without borders. A free exchange of knowledge for the common benefit of mankind.'

'Wankers,' O'Mara explained to us helpfully.

'We'd the French there, Americans galore, the Swedes, Dutch, even one or two Germans,' Wintle continued, oblivious to O'Mara's jibe. 'All of them had hope, in my opinion, and the Russians had it in bucketfuls. It was us British who were dragging our feet. We still are.'

O'Mara groaned and took a restorative pull of gin. But Ned's good smile, even if a little battered, encouraged Wintle to run on.

'It was the height of the Khrushchev era, as you will doubtless recall. Kennedy this side', Khrushchev that side. A golden age was beckoning, said some. People in those days talked about Khrushchev very much as they talk of Gorbachev now, I'm sure. Though I do have to say that, in my opinion, our enthusiasm then was more genuine and spontaneous than the so-called enthusiasm now .'

O'Mara yawned and fixed his pouchy gaze disconcertingly upon myself.

'We told them whatever we knew. They did the same.' Wintle was saying as his voice gathered assurance. 'We read our papers. They read theirs . Callow didn't cut any ice, I'm bound to say. They rumbled him in no time. But we'd Panson on cybernetics and he flew the flag all right, and we had me. My modest lecture was quite a success, though I do say it myself. I haven't heard applause like it since, to be frank. I wouldn't be surprised if they still talk about it over there. The barricades came down so fast you could literally hear them crashing in the lecture hall. "Flow, not demarcation." That was our slogan. "Flow" wasn't the word for it either, not if you saw the vodka that was drunk at the late-night parties. Or the girls there. Or heard the chat. The KGB was listening, of course. We knew all about that. We'd had the pep talk before we left, though several objected to it. Not me, I'm a patriot. But there wasn't a blind thing that any of them could do, not their KGB and not ours .' He had evidently hit a favourite theme for he straightened himself to deliver a prepared speech. 'I'd like to add here that their KGB is greatly misjudged, in my opinion. I have it on good authority that the Soviet KGB has very frequently sheltered some of the most tolerant elements of the Soviet intelligentsia.'

'Jesus – well don't tell me ours hasn't,' O'Mara said.

'Furthermore I've no doubt whatever that the Soviet authorities very rightly argued that in any trade-off of scientific knowledge with the West, the Soviet Union had more to gain than lose .' Wintle's slanted head was switching from one to another of us like a railway signal, and his upturned hand was resting on his thigh in anguish. 'They had the culture too. None of your Arts-Sciences divide for them , thank you. They had the Renaissance dream of rounded man, still do have. I'm not much of a one for culture myself. I don't have the time. But it was all there for those who had the interest . And reasonably charged too, I understand. Some of the events were complimentary.'

Wintle needed to blow his nose. And to blow his nose Wintle needed first to spread his handkerchief on his knee, then poke it into operational mode with his fingertips. Ned seized upon the natural break.

'Well now, I wonder whether we could take a look at one or two of those Soviet scientists whose names you kindly gave to Major Vauxhall,' he suggested, taking the sheaf of papers I was holding out to him.

We had arrived at the moment we had come for. Of the four of us in the room, I suspected only Wintle was unaware of this, for O'Mara's yellowed eyes had lifted to Ned's face and he was studying him with a dyspeptic shrewdness.

Ned led with his discards, as I would have done. He had marked them for himself in green. Two were known to be dead, a third was in disgrace. He was testing Wintle's memory, rehearsing him for the real thing when it came. Sergey? said Wintle. My goodnessyes, Sergey! But what was his other name then? Popov? Popovich? That's right, Protopopov! Sergey Protopopov, engineer specialising in fuels!

Ned coaxed him patiently along, three names, a fourth, guiding his memory, exercising it: 'Well now, just think about him a second before you say no again. Really no? Okay. Let's try Savelyev.'

'Come again?'

Wintle's memory, I noticed, had the Englishman's embarrassment with Russian surnames. It preferred first names that it could anglicise.

'Savelyev,' Ned repeated. Again I caught O'Mara's eye upon him. Ned peered at the report in his hand, perhaps a mite too carelessly. 'That's it. Savelyev.' He spelt it. "'Young, idealistic, talkative, called himself a humanitarian. Working on particles, brought up in Leningrad." Those were your words, according to Major Vauxhall all those lifetimes ago. Anything more I might add? You didn't keep up with him, for instance? Savelyev?'

Wintle was smiling in marvel. 'Was that his name, then? Savelyev? Well I'm blowed. There you are. I'd forgotten. To me he's still Yakov, you see.'

'Fine. Yakov Savelyev. Remember his patronymic?'

Wintle shook his head, still smiling.

'Anything to add to your original description?'

We had to wait. Wintle had a different sense of time from ours. And to judge by his smirk, a different sense of humour.

'Very sensitive fellow, Yakov was. Wouldn't dare ask his questions in the plenum. Had to hang back and pluck your sleeve when it was over. "Excuse me, sir, but what do you think of so-and so?" Good questions, mind. A very cultural man, too, they say, in his way. I'm told he cut quite a dash at some of the poetry readings. And the art shows.'

Wintle's voice trailed off and I feared he was about to fabricate, Which is a thing people do often when they have run out of information but want to keep their ascendancy. But to my relief he was merely retrieving memories from his store - or rather milking them out of the ether with his upright fingers.

'Always going from one group to another, Yakov was,' he said, with the same irritating smile of superiority. 'Standing himself at the edge of a discussion, very earnest. Perching on the edge of a chair. There was some mystery about his father, I never knew what. They say he was a scientist too, but executed. Well a lot were, weren't they, scientists. They killed them off like fruit flies, I've read about it. If they didn't kill them, they kept them in prison. Tupolev, Petliakov, Korolev - some of their greatest stars of aircraft technology designed their best stuff in prison. Ramzin invented a new boiler for heat engines in prison. Their first rocketry research unit was set up in prison. Korolev ran it.'