The first book in the Bernard Samson series, 1983

'How long have we been sitting here?' I said. I picked up the field glasses and studied the bored young American soldier in his glass-sided box.

'Nearly a quarter of a century,' said Werner Volkmann. His arms were resting on the steering wheel and his head was slumped on them. That GI wasn't even born when we first sat here waiting for the dogs to bark.'

Barking dogs, in their compound behind the remains of the Hotel Adlon, were usually the first sign of something happening on the other side. The dogs sensed any unusual happenings long before the handlers came to get them. That's why we kept the windows open; that's why we were frozen nearly to death.

'That American soldier wasn't born, the spy thriller he's reading wasn't written, and we both thought the Wall would be demolished within a few days. We were stupid kids but it was better then, wasn't it, Bernie?'

'It's always better when you're young, Werner,' I said.

This side of Checkpoint Charlie had not changed. There never was much there; just one small hut and some signs warning you about leaving the Western Sector. But the East German side had grown far more elaborate. Walls and fences, gates and barriers, endless white lines to mark out the traffic lanes. Most recently they'd built a huge walled compound where the tourist buses were searched and tapped, and scrutinized by gloomy men who pushed wheeled mirrors under every vehicle lest one of their fellow-countrymen was clinging there.

The checkpoint is never silent. The great concentration of lights that illuminate the East German side produces a steady hum like a field of insects on a hot summer's day. Werner raised his head from his arms and shifted his weight. We both had sponge-rubber cushions under us; that was one thing we'd learned in a quarter of a century. That and taping the door switch so that the interior light didn't come on every time the car door opened. 'I wish I knew how long Zena will stay in Munich,' said Werner.

'Can't stand Munich,' I told him. 'Can't stand those bloody Bavarians, to tell you the truth.'

'I was only there once,' said Werner. 'It was a rush job for the Americans. One of our people was badly beaten and the local cops were no help at all.' Even Werner's English was spoken with the strong Berlin accent that I'd known since we were at school. Now Werner Volkmann was forty years old, thickset, with black bushy hair, black moustache, and sleepy eyes that made it possible to mistake him for one of Berlin 's Turkish population. He wiped a spyhole of clear glass in the windscreen so that he could see into the glare of fluorescent lighting. Beyond the silhouette of Checkpoint Charlie, Friedrichstrasse in the East Sector shone as bright as day. 'No,' he said. 'I don't like Munich at all.'

The night before, Werner, after many drinks, had confided to me the story of his wife, Zena, running off with a man who drove a truck for the Coca-Cola company. For the previous three nights he'd provided me with a place on a lumpy sofa in his smart apartment in Dahlem, right on the edge of Grunewald. But sober, we kept up the pretence that his wife was visiting a relative. 'There's something coming now,' I said.

Werner did not bother to move his head from where it rested on the seatback. 'It's a tan-coloured Ford. It will come through the checkpoint, park over there while the men inside have a coffee and hotdog, then they'll go back in to the East Sector just after midnight.'

I watched. As he'd predicted, it was a tan-coloured Ford, a panel truck, unmarked, with West Berlin registration.

'We're in the place they usually park,' said Werner. 'They're Turks who have girlfriends in the East. The regulations say you have to be out before midnight. They go back there again after midnight.'

They must be some girls!' I said.

'A handful of Westmarks goes a long way over there,' said Werner. 'You know that, Bernie.' A police car with two cops in it cruised past very slowly. They recognized Werner's Audi and one of the cops raised a hand in a weary salutation. After the police car moved away, I used my field glasses to see right through the barrier to where an East German border guard was stamping his feet to restore circulation. It was bitterly cold.

Werner said, 'Are you sure he'll cross here, rather than at the Bornholmerstrasse or Prinzenstrasse checkpoints?'

'You've asked me that four times, Werner.'

'Remember when we first started working for intelligence. Your dad was in charge then – things were very different. Remember Mr Gaunt – the fat man who could sing all those funny Berlin cabaret songs – betting me fifty marks it would never go up… the Wall, I mean. He must be getting old now. I was only eighteen or nineteen, and fifty marks was a lot of money in those days.'

'Silas Gaunt, that was. He'd been reading too many of those 'guidance reports' from London,' I said. 'For a time he convinced me you were wrong about everything, including the Wall.'

'But you didn't make any bets,' said Werner. He poured some black coffee from his Thermos into a paper cup and passed it to me.

'But I volunteered to go over there that night they closed the sector boundaries. I was no brighter than old Silas. It was just that I didn't have fifty marks to spare for betting.'

The cabdrivers were the first to know. About two o'clock in the morning, the radio cabs were complaining about the way they were being stopped and questioned each time they crossed. The dispatcher in the downtown taxi office told his drivers not to take anyone else across to the East Sector, and then he phoned me to tell me about it.'

'And you stopped me from going,' I said.

'Your dad told me not to take you.'

'But you went over there, Werner. And old Silas went with you.' So my father had prevented my going over there the night they sealed the sector. I didn't know until now.

'We went across about four-thirty that morning. There were Russian trucks, and lots of soldiers dumping rolls of barbed wire outside the Charité Hospital. We came back quite soon. Silas said the Americans would send in tanks and tear the wire down. Your dad said the same thing, didn't he?'

'The people in Washington were too bloody frightened, Werner. The stupid bastards at the top thought the Russkies were going to move this way and take over the Western Sector of the city. They were relieved to see a wall going up.'

'Maybe they know things we don't know,' said Werner.

'You're right,' I said. They know that the service is run by idiots. But the word is leaking out.'

Werner permitted himself a slight smile. 'And then, about six in the morning, you heard the sound of the heavy trucks and construction cranes. Remember going on the back of my motorcycle to see them stringing the barbed wire across Potsdamerplatz? I knew it would happen eventually. It was the easiest fifty marks I ever earned. I can't think why Mr Gaunt took my bet.'

'He was new to Berlin,' I said. 'He'd just finished a year at Oxford, lecturing on political science and all that statistical bullshit the new kids start handing out the moment they arrive.'

'Maybe you should go and lecture there,' said Werner with just a trace of sarcasm. 'You didn't go to university did you, Bernie?' It was a rhetorical question. 'Neither did I. But you've done well without it.'

I didn't answer, but Werner was in the mood to talk now. 'Do you ever see Mr Gaunt? What beautiful German he spoke. Not like yours and mine – Hochdeutsch, beautiful.'