The Brandenburg exit – the place arranged for Fiona Samson to change from one car to the other – was on East Germany's section of Hitler's Autobahn, built to connect Berlin to Holland and all points westwards. As well as being a major East German highway, this was one of the authorized routes along which Westerners were permitted to drive to West Berlin.

On this flat region immediately to the west of Berlin the rivers have spread to become lakes. It is a region of farmland and forest, and once outside the towns the traveller finds little cobble-streeted villages where little has changed since the Kaiser's photo hung in the schoolrooms.

Even one of East Germany's two-stroke motor cars can get there from Berlin in well under an hour; for Thurkettle's powerful motor cycle it was nothing. He arrived before dark. The workers from the construction site had gone: their earth-moving machines were neatly lined up, like tanks for an inspecting general.

Thurkettle broke the lock off the door of the portable hut used by the construction gangs. He used a flashlight to check his guns and ammunition and the stainless steel butcher's hacksaw he'd brought with him. Then he put on his coveralls and plastic medical gloves and looked at the skull and its neat dentistry. That done, he sat down, watched the pouring rain and waited patiently for it to get dark.

These things never go exactly according to plan. That was the most important of the lessons he'd learned over the years. Prettyman had told him that Erich Stinnes would be collecting Fiona Samson and bringing her to the rendezvous. Someone like her would remain there.

Thurkettle had been told that someone of exactly the same build as Fiona Samson must be killed and left at the rendezvous. It was Thurkettle who thought of the idea of using Fiona Samson's sister, and he was pleased with that. She was a drug addict, and such people were easy to control. His task was to put Fiona Samson into the car with her husband and let them depart alive. He then had to kill Stinnes and the sister, bury Stinnes in the excavated ditch the roadworkers had so conveniently provided close by, and burn the car with the sister's body inside it.

The Soviet investigators would never find Stinnes' body because by the time they realized that Stinnes had not gone over the frontier with Samson, there would be a hundred tons of solid concrete and a section of Autobahn over the burial place. The burned body would be identified as Fiona Samson because the two women were very much alike except for the dentistry, and the skull he'd shown Werner had been prepared for exactly that deception. The trickiest task was decapitating the sister, but her head would have to go in the ditch with the Stinnes corpse. Otherwise the forensic team examining the car would find a burned body with two heads, and that would alert even the doziest laboratory assistant.

It all went amiss; right from the very start. Tessa – unreliable in the way that addicts usually are – did not arrive on time. Despite everything Thurkettle had arranged, she went off to Werner's fancy-dress party. Tessa should have arrived first. Thurkettle became so anxious that he went off on his motor cycle, but came back when he recognized the car with Fiona and Stinnes in it. When finally Tessa did arrive, it was in the back of the Ford van with Bernard Samson. Stinnes had arrived in a Wartburg bringing Fiona Samson and Harry Kennedy too. And who could have guessed that Bernard Samson would arrive with some lunatic from London Central who perhaps thought it would be amusing to come directly from Werner's party wearing his fancy dress? A gorilla costume! Their Ford van was there within five minutes of the Wartburg, and parked in what Thurkettle approved as a good getaway position. The Wartburg was parked nose-out, with its sidelights on. Thurkettle expected Stinnes to bring the heroin consignment out of the car but no one emerged.

Everyone seemed to be waiting for something to happen. Thurkettle remained in the darkness and watched. He was standing behind one of the bulldozers when it all started: a slim man, dressed as a gorilla, leapt from the Ford van, and started jumping around, shouting and waving a gun.

A gorilla. It looked so damned convincing for a moment that Thurkettle thought it was a real gorilla. It took a lot to surprise Thurkettle but that took him off guard. It must have taken Stinnes, or whoever was in the driver's seat of the Wartburg, off guard too, for someone switched on the car's full beams to see the gorilla more clearly.

The gorilla raised his pistol and was about to fire at the Wartburg. Thurkettle suddenly saw his reputation threatened and his fee in jeopardy. The Samson woman had to get away safely. Prettyman in London had been most specific about that. If Fiona did not arrive safely in the West, no fee would be paid beyond the small initial 'contract' payment.

So Thurkettle fired at this crazy gorilla. His silenced gun made no more noise than a carefully opened bottle of wine. But by this time Thurkettle was rattled and his shot missed.

Then the gorilla fired. He must have heard Thurkettle's shot, for he was virtually in line with the barrel, where the silencer has least effect. The glass of the Wartburg's windscreen smashed and Thurkettle thought Fiona Samson had been hurt, but then he saw her get out of the car. She shouted something, and then her doped-out sister came floating into view. Tessa came dancing, arms outstretched to display a long yellow diaphanous dress that was some sort of fancy costume.

There must be no mistakes this time. Thurkettle picked up the shotgun and aimed low. Tessa seemed to see him. She grinned as he pulled the trigger twice, hitting her with both shots. As she went down, the gorilla fired again and this time his round put out one of the Wartburg's headlights. Thurkettle didn't like the way it was developing. Given the darkness one or two of these people could get away. But he wasn't by any means certain how many people were there.

There were more shots, fired in rapid succession, a sign of nerves. Stinnes probably, he could be trigger-happy. One of them had to find a mark. The gorilla screamed, ran, stumbled and crashed into the mud. Thurkettle stayed in the darkness. Somewhere in this muddy arena Bernard Samson lurked, and Samson was a pro. Then Stinnes stepped out to make sure the gorilla was dead. What a reckless thing to do. Thurkettle remained very still in the darkness and kept silent.

'It's safe,' called Stinnes. He beckoned to a second man: a tall fellow in a smart trenchcoat: Kennedy.

'How many did they send?' Kennedy asked. He looked round nervously and the light from the single passing headlight caught his face. From his position Thurkettle could see both men clearly and identified them beyond chance of mistake: yes, Erich Stinnes and Harry Kennedy.

Then Fiona Samson walked forward. Some instinct, or understandable trepidation, made her walk so as to avoid the pool of light. London must have briefed her to go for the van, for she was heading towards it, past the men, when two shots were fired. They came from somewhere so close to Thurkettle that the sound made him jump hah out of his skin. Fiona Samson disappeared. Damn!

Bang. Some damned great handgun. Kennedy jumped back, arms flailing like a rag doll as he was knocked over, and lay in the mud as still as a bundle of old clothes. He was unmistakably dead. Sometimes it goes like that, a lucky accident and one shot is enough.

Bang. Again the cannon went off. Stinnes lurched round, firing his gun with one hand and clutching his neck with the other, the blood spraying through his fingers. It went everywhere and spattered Fiona. That shot was enough to tell Thurkettle that these were not lucky accidents. There was someone, a too damned close to him someone, who'd silently clambered up on to a piece of heavy machinery to get a better vantage point; some cold-blooded someone who didn't say hands up; someone who hadn't perfected his shooting on the range: Samson.