He lunged for Hitler, dragging him up from the couch. In a single, seamless movement, he had drawn his dagger from his belt and curled his left arm around the former Führer’s neck so that their faces were almost touching and he was using Hitler as both shield and hostage.

The honed blade touched his cold, perspiration-soaked trachea. One sideways move and the blood would rush forth. Oh yes, he could do that. It would not weigh on his conscience to kill the murderer of millions in cold blood.

It was the others that posed the problem.

He thrust the muzzle of the M3 beneath Hitler’s arm, covering the housekeeper and children. One tug of the trigger and they would be riddled with bullets. But even if his brain told his finger to fire, he knew his finger would disobey.

Hitler was making no noise. He wasn’t exactly limp, but nor was he straining to get free.

Siegfried Boden shrugged. ‘Think about it, Ami, you don’t have to do this. You don’t have to die today. We can pay you big money to walk away. Imagine how much money is behind us. Millions in Swiss accounts. Just put down your weapons and walk away. You have our word that you will be safe.’

‘What is Opa now anyway?’ Brünnhilde said. ‘Look at him. He’s just a harmless old greybeard. He is like a grandad to us. A very special grandfather – and we have sworn to look after him.’

‘This is madness. He is nothing to you. You’re young. A new Germany is about to be born and you should be a part of it.’

Suddenly the full, hideous enormity of his situation hit him. He had found Adolf Hitler, the most wanted man in the world, the worst mass murderer in history, and he was standing here with a knife to his throat, holding him in his arms, confronted by two lethal children.

With two split-second motions he could kill the Führer and those protecting him and the world would applaud.

The history books would say that he was the man who had rid the world of the tyrant. And the others? Collateral damage, just like the innocents killed in the bombing of Hamburg and Rotterdam, London and Warsaw.

And he couldn’t do it. The bomber crews had done it every day, and he couldn’t.

If only Hitler had been guarded by SS men. That would have been easy. He would have shot them without hesitation.

The housekeeper gave a heavy sigh and shook her head. ‘There will be no bloodshed in here.’ She addressed Siegfried and Brünnhilde. ‘Go and wait outside. The American will have to leave at some stage, and he can’t get past you. Let his blood feed the wildflowers and the grass.’

‘I don’t know, Frau Fuchs,’ the boy said doubtfully.