If Churchill’s movements were significant, then Hitler’s were even more so. On June 6, 1940, after frantic construction work carried out at short notice, a secret meeting-place had been improvised in Belgium at the tiny frontier zone village of Brûly de Pesche. The air-raid shelter there was still damp from freshly poured concrete and Hitler refused to go inside it. Here the airstrip was no more than a meadow big enough to land a small communications aircraft, so Churchill’s twin engined de Havilland Flamingo had landed near to Hitler’s Junkers at Rocroi, just across the border in France. The Fieseler Storch was already warmed-up when Churchill landed, and by the time the little plane was airborne Churchill’s Flamingo was shrouded in camouflage nets on the far side of the airfield.

Significant too was the fact that the Brûly de Pesche headquarters was used once only, for this meeting with Winston Churchill. The whole elaborate place was constructed solely for this secret summit meeting and after its few days of importance was left to rot.

On June 17, his hopes of a British request for a ceasefire faded, Adolf Hitler travelled to Munich where, in the Prince Carl Palace, Benito Mussolini was hoping to hear that the British would no longer resist his armies in Africa. By June 21 the fighting in France was all but finished. Hitler was motoring through the Forest of Compiègne in his open Mercedes, arranging that the German army engineers bring out of its museum the railway coach in which the Germans had signed a peace with France after the First World War. On June 22 the French armistice was signed in that same Pullman car. The brief chance of early peace between Britain and Germany had gone for ever.

Stuart went through the papers again and again. He looked at the Waffen SS and army unit war diaries that the War Office had provided from their archives. He looked at the tall stack of biographies that described Adolf Hitler’s life in such minute detail. He looked at xerox copies from the Berlin document centre and the West German archives. He looked once more at the published memoirs. Once the truth was known, so many other mysteries were solved. For instance, why had the twelve Hawker Hurricanes that escorted Churchill’s aircraft out of Briare on June 11 not been sent out to escort him for the return flight the next day? [3] It was especially puzzling in the light of the RAF’s order of battle, which showed that six Hurricane squadrons were based in France until June 17. The fighters would not even have had to cross the Channel to get to Briare.

The real answer was obvious now, but the official reason had been given as bad weather. (It hardly fitted with the fact that on this same day RAF aircraft had found the weather and visibility good enough to make low-level bombing attacks on bridges over the Albert Canal in nearby Belgium, to say nothing of long-range bombers flying from England to Turin.) The fact was that the Hawker Hurricane pilots might, by some error or disruption of the schedule, have glimpsed the unthinkable.

They would have seen a Staffel of Messerschmitt Bf 109 Es flying close escort on Churchill’s unarmed Flamingo. The aircraft, from Jagdgeschwader 51, had been ordered to this task by direct order to Luftflotte 2 headquarters from the Führerhauptquartier. These German fighters circled the airfield until Churchill’s aircraft was in the air, and then protected him across the German lines into French airspace.

Significantly, it was the Luftwaffe high command in Berlin (Ob.d.L.) which had issued the special instructions for this small tactical mission. Stuart turned the teleprinter message over in his hands. The cryptic language of the signals unit at Luftflotte 2, which passed the secret message to IX Fliegerdivision HQ, did little to hide the nature of the instruction. No routing was mentioned in the message but HQ insisted that all pilots must be specially briefed that the Sonderflug must be kept safe at all costs. No fighter pilot must leave the escort formation to attack enemy targets no matter how tempting. The Geschwaderkommodore, the message continued, was to lead the mission in person. Failure to carry out the terms of this ‘commander-in-chief’s order’ would mean court-martial for all concerned.

Adolf Hitler had done everything in his power to ensure that no ghastly calamity mar this chance of the British Commonwealth’s giving up the struggle so that he could become the undisputed master of Europe.

Boyd Stuart closed the file, and pressed the buzzer to summon the duty archive clerk. Suddenly he felt tired and rather old.

There were plenty of larger boats to be seen on Lake Geneva that summer but Die Zitrone was a fifty-foot motor yacht with factory-fresh diesels, modern radar and a powerful launch swinging from the stern davits. Die Zitrone cruised very slowly along the south side of the lake, keeping close to the shore, but not dangerously so. On the afterdeck two men were seated at a table with a Campari in one hand and Zeiss binoculars in the other. From time to time they would raise the binoculars to look at the shoreline.

It was a warm day, the first Saturday of August. One of the men was dressed in dark trousers and a white shirt with a neat monogram on the pocket flap-as used to mark expensive made-to-measure garments. A blue yachting cap completed the sort of informal outfit favoured by owners who chartered and sailed their own yachts for their clients and was calculated to indicate superior skills while maintaining social equality.

The second man wore a striped shirt and grey shorts. It was hot and he was sweating. From time to time he ran his hand through his closely cropped hair. On the table in front of him there was a tape recorder. From it came a thin black lead which ended at his shirt collar where a tiny microphone was clipped close to his mouth. ‘The first boatload of men must stay at the lake shore until all the boats are secured,’ Willi Kleiber said into the microphone. ‘The Pitman house is one hundred and fifty metres from the landing stage. Any boats found at the landing stage must be totally disabled by the landing party from boat one. No one will move from their position until all boats are secured and contact has been made with the party arriving by road. The two advance men of the road party will use red flashlights to identify themselves. The two advance men of boat one will use only green flashlights.’ He switched the tape recorder off and took one last look at the big lakeside house of Colonel John Elroy Pitman the Third, before Die Zitrone steered away northwards to cross the lake.

It was a hot, cloudless day. The mountains were crisply drawn against the blue sky and very close, or so it seemed. The two men put down their binoculars and put on their sunglasses. They sat for a moment, still dazzled by the harsh reflection of the sun off the flat water.

‘It will be easy,’ said Willi Kleiber.

‘I don’t like it,’ said Max Breslow. ‘We still don’t know what the documents are like. If they are all contained in those metal filing cases, it will take all night to get them out of the house and loaded on to the trucks.’

‘Of course it will,’ said Kleiber. ‘At least it would… if that’s what I intended to do.’

‘When then?’

‘We’ll take possessions of the house, I’ve told you so. Do you think I’ve changed my mind?’ said Kleiber. ‘We’ll hold it for two or three days… ’ Kleiber saw that Max was about to argue, ‘a week, if it takes a week. We’ll stay there as long as we have to.’

‘My God, Willi. You don’t know what you are saying.’

‘I’m a gambler, Max. I always have been.’

‘Stay there? Holding those Americans captive?’

‘You saw what it’s like, Max. There will be no difficulty in embarking our people from the lakeside. It will be quiet and discreet. They have only to come from Coppet on the far side of the lake. One carload of our best people will arrive at the Pitman house by road. No one in the village will hear shooting, there will be no lights.’