'What have they found out?'

He meant the security people.

'Nothing, as far as I know.' I hadn't told him I'd been to look at the body.

'They still think it was suicide?'

'I don't know. I haven't asked them.'

He went back to his papers. He was a professor of biology, he'd told me, at the Academy of Sciences in Akademgorodok, south of Novosibirsk.

Just before ten an announcement was made over the public address system. This is the chief of security. We shall be stopping briefly in half an hour from now, at thirty minutes past ten o'clock. Nobody will be permitted to leave the train, and passengers are instructed to keep away from the doors. I will repeat: no passengers will be permitted to leave the train.

I was reminded again that if anything went wrong with the mission, if I needed continued freedom of movement to keep it on track and make progress, I might be forced to do it in the confines of these narrow corridors, and might find that when I'd boarded this train in Moscow I had walked into a trap. The only way out of it, even if I could reach an unattended door, was across the limitless wastes of Siberia.

'There'll be a full enquiry,' Slavsky said, 'I imagine.'

'Yes,' I said.

In twenty minutes the huge momentum of the Rossiya began dying, and the beaker of water on the small collapsible table was sliding gradually towards the edge. A distant scream came from the locomotive ahead of us, and the steel couplings began banging as the tension came off.

'Would this be a town?' I asked Slavsky. He'd said he did this trip three times a year.

'Yes — ' looking up from his papers — 'a small one. There are several between Tyumen and Novosibirsk.'

Small buildings swung past the windows, many of them with their blue or green paint faded and peeling away. We heard geese raising a clatter, and the faint shout of a farmer's boy. Inside the train, people were crowding along the corridors, staring through the snow-encrusted windows.

We will repeat our previous announcement. No one will be permitted to leave the train when it comes to a stop. Passengers must keep the doors clear.

Boris Slavsky was shuffling his papers into some sort of order and stuffing them into his big leather case.' I hope this enquiry won't hold us up,' he said.' they've got a little dinner party planned for tonight in Novosibirsk.' He trailed off with a modest mumble:

Celebrating my homecoming.'

'How nice for you,' I said.

There wouldn't be any celebrating in London tonight if I could send a signal through from Novosibirsk when the Rossiya made its stop. The board for Meridian would be looking bleak under the floodlights. Russian contact deceased. Opposition hit suspected. Executive assumed in hazard.

That would depend — the hazard thing — on whether any serious notice had been taken of the fact that I'd talked to Zymyanin not long before he was killed. It would also depend on whether the opposition had in fact struck some kind of spurious deal with Zymyanin — perhaps for his life — and got him to talk before they killed him. And finally it would depend on how well or otherwise my cover would stand up to a homicide investigation.

'I have two grandchildren, 'Slavsky said. He was perched on the edge of his bunk and looking up at me with his eyes magnified by their glasses.

'You don't look old enough,' I said.

'Thank you.' He looked down, modestly.

I'd begun to find Boris Slavsky rather charming, and it would have been nice to talk to him some more between here and Novosibirsk.

I didn't think that was going to be possible.

The couplings out there raised a whole peal of bells as the carriages started shunting, and I braced myself against the bulkhead as the train came to a halt. I got a towel and cleared a hole in the fogged glass of the window and saw two police cars standing in the snow beyond the rustic platform, their coloured lights revolving. Dark figures moved about; I couldn't tell whether they were in uniform.

A generator began running and hydraulic pipes hissed. The people lining the windows of the corridors were talking, their tone quietly excited, reminding me of a murmuration of starlings along a telephone wire. Then there was the tramp of boots on the platform and voices sounded, some of them from inside the train; then finally a door was slammed shut.

'Are they the police?' Slavsky asked.

'Yes,' I said.

It was 2:14 when a provodnik put his head into our compartment, a man, not Galina.

'Shokin, Viktor?'

'Yes.' I got up. I'd been looking at one of Slavsky's books, at a coloured illustration of the nervous system of the Drosophila melanogaster, while I was mentally going through the details of my cover.

I followed the provodnik along to the dining car. The corridors were almost empty: there'd been repeated announcements asking passengers to keep to their compartments unless it was essential to leave them. The Rossiya had taken on a different atmosphere since we'd stopped at the small town, something like that of a ship running into trouble in mid-ocean.

We were now halfway from the town to Novosibirsk, and moving into the half-light of darkening skies. It was said there was another snowstorm, a big one, hanging over central Siberia.

The tables had all been cleared in the dining car except for their white linen cloths, some of them still stained. The smell of sour cooking seeped in from the galley.

'You are Shokin, Viktor Sergei?'

'Yes.'

There were something like twenty uniformed policemen dispersed among the tables, sitting in their booths opposite the passengers with big yellow notepads between them. Some of the train's security guards were protecting the exits.

'Sit down, please. I am Chief Investigator Gromov.'

A man in his fifties, thick-bodied and square-faced, a black mole near the side of his nose, his eyes bland and patient as he studied me. He'd left his greatcoat on, despite the steamy heat in here. I sat down.

A chief investigator. This table was at the end of the dining car, the one where the major interest was centred, perhaps. They'd been sifting through probably two or three hundred passengers since they'd come aboard, and hadn't even reached Car No. 9, two along from my own.

I'd been specially selected.

'Do you know what has happened on the train?'

'Yes,' I said.

'Tell us what has happened, please.'

Two other investigators were at the table, one sitting beside me and the other opposite. The one opposite was quite different from his chief: lean and pale-faced with colourless eyes, a thin line for a mouth, a sharp nose-bone. He was also much younger, would have come up fast through the ranks, to be sitting here with the chief of homicide investigation.

'A dead man was found,' I said, 'early this morning.'

'Was it an accident?'

His eyes were a nutty brown, the chief's, with gold lights in them; they could be the eyes of your favourite uncle, the one who always brought you things when you were a whipper-snapper and he came to pay a visit. But sometimes as he watched me the eyes of Gromov deadened, and the light in them went out, and that was when I felt worried, because he was slipping a mask over them.

'There are a lot of rumours,' I told him. 'Some say he committed suicide, others say he was murdered.'

'And which do you think is the truth?'

'You're asking me to choose between rumours?'

He picked up a pen, a cheap red ballpoint with a tuft of frayed string on it; perhaps he'd pulled it away from something. He began making notes on the big yellow pad, not all the time, just now and then as I went on giving him the answers to his questions as best I could. He talked to me as if this were the first I'd heard of any incident on the train, and I understood why: he wanted to see if I knew something that none of the other passengers did, and hoped I'd let it out unintentionally.