'Of course. Where shall I find you?'

'We shan't leave this carriage. Or you can tell the attendant.'

Karasov was a Latvian, with a facial resemblance to a northern European or an American. That was why the KGB man had taken so much interest in me.

'I'll keep my eyes open,' I said.

He nodded and went back into the corridor.

It was another half an hour before I knew they'd got me. Not the KGB. The Rinker cell. They were here and they were on to me and there was nothing I could do to reach the objective or keep Northlight running or save myself. Nothing.

Gromyko warns: we are reaching the point of no RETURN. Picture of Gromyko, one finger held up, face blank as usual.

It was the only story on the front page of Pravda and the headline was twice as big as usual.

Let it be stated once again. The obstinacy on the part of the Western Powers to admit to the fact that the United States of America committed what was tantamount to an act of war, in sending an armed nuclear submarine into Soviet waters, is now offering a threat to world peace of a magnitude that has never before faced mankind.

In times of normal diplomatic relations the affair of the US Cetacea would have brought the two great powers to a situation of precipitate crisis. When it is considered that the Vienna meeting was agreed upon in order to alleviate a- crisis in diplomatic relations that already existed before this irresponsible and dangerous act was undertaken, it will be seen even by the least intelligent of America's allies that only a miracle can now save the Vienna summit meeting, and the world from final and irrevocable disaster.

One of them was the man with the shapeless leather bag.

Until this is clearly understood by the intransigent West, the world must remain poised on the edge of an abyss in whose depths lies the grave of civilization as we know it today.

The other was the man with the briefcase, but he wasn't watching me now. I was holding the newspaper to cover the whole of my face except when I turned the pages. Then I checked his image.

It had taken me half an hour to realize what was happening because they were working in shifts, one at a time, and using the interior window glass of the compartments and the windows across the corridor to give them a double mirror effect.

Only a miracle can now save the Vienna summit meeting, so forth. Dear Comrade Gromyko, have a little patience, for Christ's sake. Miracles take a little longer, you know that.

But I wasn't, in fact, feeling terribly confident now of pulling one off. What we must never allow to happen had happened, on pressure from Control. Although I could understand the cause of that pressure — the front page of Pravda had spelt it out clearly enough — the fact remained that the executive in the field had been forced to move into a red sector without being sure he was clean in terms of surveillance and was on his way to a critical rendezvous and taking with him two components of a formidable opposition cell.

There was also a third man.

I didn't have time to worry about the third man because the other two had me in a surveillance pincer movement, but one thing about him was interesting. He wasn't working with the other two. He wasn't with the Rinker cell at all.

I knew this because I'd become aware of him earlier, soon after the train had started off, and I'd mapped his rather elaborate movement patterns: when I'd gone along to the restaurant car for the paper he'd sought immediate cover and didn't show up again until I was back in my compartment, when he'd used another passenger as a shield as he'd come past to check on me. It wasn't that he was inefficient: it was all he could do in this kind of closed environment with only a narrow corridor as the terrain. He was under an added strain, and I'd noted this soon after he'd surfaced.

He not only knew I was under surveillance by the Rinker people. He had to keep it from them, as well as from me, that I was his target too.

In the normal way I would have been extremely interested in the fact that a second opposition network had sent an agent into the field but he was already out of the running because the Rinker cell was on to me and they wouldn't let me go and if I tried to lead them anywhere except directly to Karasov they'd close in and trap me and put me under a light and work on me until I betrayed my objective and blew the mission to bits.

There wasn't any question about this in my mind as I watched the image in the double mirrors, the face of the man who was sitting three compartments along from me with his head tilted back against the quilted upholstery and his eyes apparently closed. His cell was professional and they'd already lost a man and they'd moved in again as if nothing had happened. They wanted Karasov as badly as I did, as London did. Somewhere eke a mission control had sent his people into the field with instructions to find our sleeper.

I began reviewing the environment, but there was nothing here that you wouldn't find in most long-distance trains across the vast expanse of Soviet Russia: doors, windows, brass rails, glass-shaded lamps and upholstered seats, leather straps and racks of netting for small baggage, the emergency chain running through the compartment, glazed posters proclaiming work targets and industrial scenes, a woman in a head scarf, a man in a worker's cap. There wasn't anything that would make a weapon useful enough to offer decisive advantage in a close encounter, nothing better than my own hands; and if I finally made up my mind to draw the opposition into my own immediate vicinity and make a last-ditch attempt at dealing with them and eliminating the threat to Northlight I wouldn't be able to do it without alerting the KGB.

The only choice I had was to close down the mission and leave the field and try to survive.

He'd taken over his shift ten minutes ago, and although he was watching my reflection from between his half-closed eyelids his attention would be less acute than when he'd changed places with his partner. Static surveillance is fatiguing; on the move there is the physical stimulus offered by the need to keep the target in sight and not lose him, but to sit in a rocking train with your head against the cushions and your eyes half-closed is wearying and even mesmeric: the mind plays tricks, and that man in the mirrors wouldn't be absolutely certain that when I moved, it wasn't in his imagination. He would react, by moving himself.

If he didn't, it would be easier, for me.

I got up and kept his mirrored image in sight and made to turn to my left out of the compartment but his head moved and I abandoned the first choice and turned right instead, initiating the more dangerous play and walking past him along the corridor with my head turned away to look through the windows, not because I could hope to conceal my identity at this late stage but because it was the natural thing to do. The scene out there was eerie; there was no true daylight yet but the edge of the snow cloud was drawing away from the northeast and leaving a shimmering luminosity across the face of the hills, and from the huddle of buildings in the valley there was smoke rising from fires that in the winter here would never go out. The light was so strange in its quality that it could be either dawn or dusk or even full moon; in this region I was already finding that the only temporal constant was provided by my own biological clock.

He didn't turn his head as I walked past his compartment; in reflection he could follow me with his eyes as far as the end of the carriage and he'd only get up and take a stroll if I went further than that.

The panel on the toilet door read Unoccupied and I went in and shut the door and locked it and got my heavy coat off because the window was small and I wasn't certain I could squeeze through it. They were larger in the compartments but if I'd left my seat and opened the window he would have heard it and been along here very fast. I'd checked this toilet as soon as I'd got onto the train because it was the only place where I could break any kind of surveillance and make an escape if I had to. The air outside was below freezing and the window frame was shrunk to a loose fit and slid upwards when I pulled on the strap.