A few years earlier Bormann had been a relatively minor cog in the Nazi machine, the sort of man Himmler looked down on and used for his own ends. But Bormann had moved on, had latched on to Rudolf Hess, then Hitler himself, leapfrogging almost all those who once despised him. Bormann was no longer the coming man. He was the man, the power behind the throne. Himmler, like every other potentate in the Party, now loathed and distrusted the oily Martin Bormann. But had to defer to him if he wished to get the Führer’s ear.

Today, Spahn had to find out the truth. The American diplomat had been stopped at the border and was on his way back to Berlin, under escort. In a few hours’ time, Spahn would make it his business to be at the railway station to welcome him personally – and escort him to the cellars of 8 Prinz-Albrecht-Strasse where he could sample the pleasures of enhanced interrogation. The embassy would never know. Vanderberg had embarked on the train for Switzerland but hadn’t arrived. It would be a mystery. Many people disappeared in the night and fog of Germany at war. Few dared ask questions.

But first, there was Otto Kalt. He had had long enough at liberty. Time for him to come in and talk.

Horst Spahn pulled on his leather greatcoat and summoned his young assistant, whom he liked to call Babyface, after hearing the name in an American newsreel reporting the death of a gangster, Baby Face Nelson. It amused him to give his assistant a notorious gangster’s name, because his skin was fresh and smooth and the boy had such bright blue eyes. He didn’t even drink alcohol.

Baby-face entered the office, clicked his heels and saluted.

‘Heil Hitler, Herr Spahn.’

‘Ah, Baby-face, we have important work to do. Something to get us out of this accursed office.’

‘Of course, sir.’

‘Good boy. Order a car – and bring your weapon.’

*

After phoning Bormann from a telephone kiosk close to his guest house in a side street off Alexanderplatz, Otto Kalt hunched into his coat, pulled his hat down over his brow and headed out into the heart of Berlin. It was another working day, the roads full of trams, bicycles and military traffic.

Through the gusting sleet, he noted the SD agent sheltering in the cinema doorway across the road, where a Hans Stüwe film was advertised, but Kalt ignored his pursuer, dug his hands deeper into his pockets and hastened westwards, over the Spree on to the museums island, then to the broad stretch of Unter den Linden. He knew the SD man was still following him; he could feel his presence without looking. No one could pursue Otto Kalt undetected.