When, we were going up in the lift I heard the bomb-disposal team in the basement being told to pull out. Foster stood idly watching the wall sliding downwards on the other side of the gates. His breathing had become heavy, the only sign that he was disurbed. There was a city-wide search going on and he'd just passed me through a cordon and he hadn't liked that.

It was the big double-windowed room at the end of the third floor and he used his key and I told him to go in first, then I followed.

Define, infiltrate, destroy. I had defined and was now infiltrating.

I picked up the phone and told them the situation was in hand and that I'd be phoning at fifteen-minute intervals.

Foster got his keys out but I took them from him: there could be a gun in a drawer and I was going to be too busy to stop him playing about.

'We really ought to discuss the position you're in, old boy. You'd thank me, later.'

'Take that chair over there and sit on it.'

Three reasons for utmost haste: Given enough time I knew that Foster could out-think me. The sector was still bright red until I could get him to my own base. Merrick or the guard at the Hotel Cracow might telephone the Commissariat to ask if things were all right and if I answered their call they'd want to speak to Foster and I'd have to let them or they'd know things weren't all right and he'd use an alert-phrase and I wouldn't be able to stop him.

The safe came open with the two keys on the separate ring of Voskarev's bunch and I began with the top metal drawer because it was logical to file recent and current material highest.

Most of the stuff was in Russian but none of it encoded and I went for main headings and serial numbered collations and found one specific document summarising the whole of the operation under sections Preliminary Evidence — Prima Facie — Integration of Testimonies — Dossier of Accused — Summary of Charges.

The name N. K. N. Voskarev appeared throughout with the title of Chief of Enquiry and the name of Colonel A. S. Foster began appearing on the reports dated later than January 16 which was the day he'd flown in from Moscow. Two other names were featured.

My senses were atrophying to a slight degree: the sound of the traffic seemed muffled and the light in here was keyed lower. Quite normal, the effect of sudden concentration as the typed symbols jumped and the mind span, incapable of containing this scale of significance.

Movement and my eyes flicked but he was only crossing his legs. In reflex I said softly:

'Sit still.'

I was looking again at the document.

So here it was: the programme I'd sensed was running in the silence and in the dark, smooth and massive and perfectly engineered, designed to protect the East-West talks from abortive collapse in the event of insurgence by the people of Poland and subsequent control of the capital by armed force under the provisions of the Warsaw Pact.

Precis: a special tribunal to be convened in Moscow for the immediate trial of a Western agent sent into Warsaw for the express purpose of activating the interests of an international imperialist conspiracy. Indictment: inciting dissension and revolt, providing clandestine liaison with Western factions, conveying assurances of diplomatic support from capitalist powers.

The trial to be attended by international correspondents with all facilities required to make manifest the guilt of the accused and the gravity of his acts.

A show trial on the Garry Powers scale with a scapegoat dragged into the limelight and butchered on the block of political expedience. A man with two names.

P. K. Longstreet, alias Karl Dollinger.

'There's nothing,' I heard Foster saying, 'you can do about it. Because you can't leave Poland.'

I went through the rest of the drawers.

He was standing behind me.

'Get over there and sit down, damn you.'

Angry because I'd let him move without my seeing him. Postpone all thoughts about the document until the sector was green, otherwise highly dangerous.

'I'm not going to do anything, old boy.' But he couldn't get his tone right. ‘We're alone here, and there might not be another chance like this. We can talk the whole thing over and do a deal on the quiet. I'll accept your word and you can accept mine. Give me a brief confession and I can arrange that you won't get more than three years, good conduct, special remission, you know the drift. Otherwise it's for life. Now do be sensible.'

I tugged at the last drawer but it was locked and I had to open it with one of Voskarev's keys. Then they were in my hand: 35mm strip of negs and a set of prints. I'd always thought it was how they'd done it, with photographs.

The streets looked different but not because of the new snowfall: there weren't so many people about and the traffic was thinning; between Praga and the city centre there was a darkened car standing at almost every intersection. Those who didn't want to be involved were keeping indoors and those who were waiting for midnight were lying low.

No one stopped us: the car carried police-plates.

There'd been a briefcase in the office and I'd cleared it out and refilled it with the stuff I wanted and it was on the carpeted floor with Voskarev's. The main document was on my lap and I leafed through it because there might be a chance to summarise the key facts in signals before I had a go at breaking a frontier. That would be when they'd get me, if I reached that far. Voskarev was working satisfactorily as a hostage but there was a deadline on that: he and Foster weren't officially involved in the counter-insurgent operations but they were in liaison with the police divisions and they'd be reported as missing, any time now.

'After all, we only need to prove our point that the uprising was incited by the West. We've nothing against you personally.' His smile had great charm in it and his tone was patient. 'Once you've been convicted you'll be of no further use to us — sorry to put it that way but I'm sure you understand — so there'll be no point in taking it out on you afterwards We're not spiteful, you know.’

He was on the tip-up seat: he seemed to like it there. I remembered something about back-trouble, a slipped disc or something: at parties he always chose an upright chair. I said:

'You couldn't have used Merrick, didn't you know that?' On the relevant pages of the document Merrick's name had been crossed out and Longstreet written above it by hand. 'He's got diplomatic immunity… The most you could have done was kick him out of the country.’

'Generally speaking yes, but we'd have made sure he'd elect to go on trial. That's why we chose him, instead of a known agent like Browning of M.I.6 — he's piddling about at the Embassy. I expect you're aware of that.'

'I never know anything about M.I.6.'

He gave a soft laugh. 'Same old thing, the departments in London don't hit it off, do they, never have. But young Merrick was just the job, you see: we wanted to create an inexperienced man and groom him for stardom. Someone we could rely on to say the right things at the trial. Then you turned up.'

'Supposing you can ever get me inside a tribunal, you think I'll say all the right things?’

'You don't need to. You've been incriminating yourself since the day you flew in, and it's all down there in the reports sent in by Merrick. It won't really matter what you say.'

Lights reflected in the glass division and I watched them and they steadied and followed for two blocks through the central area past Ogrod Saski Park and I began sweating because the minute Foster was reported missing the Moskwicz would become a trap.

'I don't think it's a police car, old boy. But it will be, sooner or later.' He leaned towards me and said with absolute sincerity: 'You'll have to accept my little offer, so you ought to do it now, because don't you see you're only adding to the charges, playing right into their hands? I'll try telling them I went with you to the Commissariat of my own free will, but old Vosky's going to bleat out the whole story. You must see you're making things difficult for me.'