The third book in the Bernard Samson series, 1985

'Cheer up, Werner. It will soon be Christmas,' I said.

I shook the bottle, dividing the last drips of whisky between the two white plastic cups that were balanced on the car radio. I pushed the empty bottle under the seat. The smell of the whisky was strong. I must have spilled some on the heater or on the warm leather that encased the radio. I thought Werner would decline it. He wasn't a drinker and he'd had far too much already, but Berlin winter nights are cold and Werner swallowed his whisky in one gulp and coughed. Then he crushed the cup in his big muscular hands and sorted through the bent and broken pieces so that he could fit them all into the ashtray. Werner's wife Zena was obsessionally tidy and this was her car.

'People are still arriving,' said Werner as a black Mercedes limousine drew up. Its headlights made dazzling reflections in the glass and paintwork of the parked cars and glinted on the frosty surface of the road. The chauffeur hurried to open the door and eight or nine people got out. The men wore dark cashmere coats over their evening suits, and the women a menagerie of furs. Here in Berlin Wannsee, where furs and cashmere are everyday clothes, they are called the Hautevolee and there are plenty of them.

'What are you waiting for? Let's barge right in and arrest him now.' Werner's words were just slightly slurred and he grinned to acknowledge his condition. Although I'd known Werner since we were kids at school, I'd seldom seen him drunk, or even tipsy as he was now. Tomorrow he'd have a hangover, tomorrow he'd blame me, and so would his wife, Zena. For that and other reasons, tomorrow, early, would be a good time to leave Berlin.

The house in Wannsee was big; an ugly clutter of enlargements and extensions, balconies, sun deck and penthouse almost hid the original building. It was built on a ridge that provided its rear terrace with a view across the forest to the black waters of the lake. Now the terrace was empty, the garden furniture stacked, and the awnings rolled up tight, but the house was blazing with lights and along the front garden the bare trees had been garlanded with hundreds of tiny white bulbs like electronic blossom.

'The BfV man knows his job,' I said. 'He'll come and tell us when the contact has been made.'

'The contact won't come here. Do you think Moscow doesn't know we have a defector in London spilling his guts to us? They'll have warned their network by now.'

'Not necessarily,' I said. I denied his contention for the hundredth time and didn't doubt we'd soon be having the same exchange again. Werner was forty years old, just a few weeks older than I was, but he worried like an old woman and that put me on edge too. 'Even his failure to come could provide a chance to identify him,' I said. 'We have two plainclothes cops checking everyone who arrives tonight, and the office has a copy of the invitation list.'

'That's if the contact is a guest,' said Werner.

'The staff are checked too.'

'The contact will be an outsider,' said Werner. 'He wouldn't be dumm enough to give us his contact on a plate.'

'I know.'

'Shall we go inside the house again?' suggested Werner. 'I get a cramp these days sitting in little cars.'

I opened the door and got out.

Werner closed his car door gently; it's a habit that comes with years of surveillance work. This exclusive suburb was mostly villas amid woodland and water, and quiet enough for me to hear the sound of heavy trucks pulling into the Border Control point at Drewitz to begin the long haul down the autobahn that went through the Democratic Republic to West Germany. 'It will snow tonight,' I predicted.

Werner gave no sign of having heard me. 'Look at all that wealth,' he said, waving an arm and almost losing his balance on the ice that had formed in the gutter. As far as we could see along it, the whole street was like a parking lot, or rather like a car showroom, for the cars were almost without exception glossy, new, and expensive. Five-litre V-8 Mercedes with car-phone antennas and turbo Porsches and big Ferraris and three or four Rolls-Royces. The registration plates showed how far people will travel to such a lavish party. Businessmen from Hamburg, bankers from Frankfurt, film people from Munich, and well-paid officials from Bonn. Some cars were perched high on the pavement to make room for others to be double-parked alongside them. We passed a couple of cops who were wandering between the long lines of cars, checking the registration plates and admiring the paintwork. In the driveway – stamping their feet against the cold – were two Parkwächter who would park the cars of guests unfortunate enough to be without a chauffeur. Werner went up the icy slope of the driveway with arms extended to help him balance. He wobbled like an overfed penguin.

Despite all the double-glazed windows, closed tight against the cold of a Berlin night, there came from the house the faint syrupy whirl of Johann Strauss played by a twenty-piece orchestra. It was like drowning in a thick strawberry milk shake.

A servant opened the door for us and another took our coats. One of our people was immediately inside, standing next to the butler. He gave no sign of recognition as we entered the flower-bedecked entrance hall. Werner smoothed his silk evening jacket self-consciously and tugged the ends of his bow tie as he caught a glimpse of himself in the gold-framed mirror that covered the wall. Werner's suit was a hand-stitched custom-made silk one from Berlin 's most exclusive tailors, but on Werner's thickset figure all suits looked rented.

Standing at the foot of the elaborate staircase there were two elderly men in stiff high collars and well-tailored evening suits that made no concessions to modern styling. They were smoking large cigars and talking with their heads close together because of the loudness of the orchestra in the ballroom beyond. One of the men stared at us but went on talking as if we weren't visible to nun. We didn't seem right for such a gathering, but he looked away, no doubt thinking we were two heavies hired to protect the silver.

Until 1945 the house – or Villa, as such local mansions are known – had belonged to a man who began his career as a minor official with the Nazi farmers organization – and it was by chance that his department was given the task of deciding which farmers and agricultural workers were so indispensable to the economy that they would be exempt from service with the military forces. But from that time onwards – like other bureaucrats before and since – he was showered with gifts and opportunities and lived in high style, as his house bore witness.

For some years after the war the house was used as transit accommodation for US Army truck drivers. Only recently had it become a family house once more. The panelling, which so obviously dated back to the original nineteenth-century building, had been carefully repaired and reinstated, but now the oak was painted light grey. A huge painting of a soldier on a horse dominated the wall facing the stairs and on all sides there were carefully arranged displays of fresh flowers. But despite all the careful refurbishing, it was the floor of the entrance hall that attracted the eye. The floor was a complex pattern of black, white and red marble, a plain white central disc of newer marble having replaced a large gold swastika.

Werner pushed open a plain door secreted into the panelling and I followed him along a bleak corridor designed for the inconspicuous movement of servants. At the end of the passage there was a pantry. Clean linen cloths were arranged on a shelf, a dozen empty champagne bottles were inverted to drain in the sink and the waste bin was filled with the remains of sandwiches, discarded parsley, and some broken glass. A white-coated waiter arrived carrying a large silver tray of duty glasses. He emptied them, put them into the service elevator together with the empty bottles, wiped the tray with a cloth from under the sink, and then departed without even glancing at either of us.