And there was another matter of an equally practical nature – he had no idea whether this place contained a lockable room. This dark den of the the former Führer would certainly not serve such a purpose; even if the door could be locked, the shutters could easily be opened and the windows broken to make their escape.

The boy was grinning at him. Wilde’s blood ran cold. There was a gun in the boy’s hand – a Luger by the look of it. He had his finger in the trigger guard and he began to spin the pistol slowly like a gunslinger in a cowboy movie.

‘Will you shoot us?’ the boy asked, then he and his sister doubled up laughing.

If Heck was here he would kill the boy and girl and the two adults in a heartbeat. But Tom Wilde was not Heck. He could no more shoot these two children and the housekeeper than his own wife and son.

‘My name is Siegfried,’ the boy said. ‘And this is my sister Brünnhilde.’

‘Siegfried, you look like a sensible boy. I don’t want anyone to get hurt. Not even him.’ He indicated Hitler. ‘He must face interrogation and trial. So cooperate, and no harm will come to you. Do you understand?’

‘Oh yes, we understand, don’t we, Hildy?’

Now Wilde saw that she, too, had a pistol. It weighed heavily in her dainty child’s hand, but he had no doubt that she knew how to use it.

‘You must know of course that we could never allow Opa to be taken prisoner,’ the girl said. ‘Do you imagine that we could allow him to be displayed in some cage for the crowds to gape at, and then be slaughtered like a hog?’

‘Perhaps it would be better if you put your weapon down,’ the housekeeper said to Wilde. ‘There’s really nothing you can do.’

‘We know every metre of these mountains and this alm,’ the boy continued. ‘And I can promise you that no one is coming to help you.’

Wilde had backed away so that he was now standing within inches of Hitler. He could smell the man’s unwashed body, almost feel the globules of sweat on his pale, unhealthy brow. He was simply sitting there, playing with his toys like an infant, unaware of the real-life drama being played out by the others in the room. Wilde wasn’t even sure that he understood the conversation or its implication for him.

Instinct told him that the children would kill without hesitation; so would Frau Fuchs. Perhaps they had done so before. He was facing three killers and some inconvenient spark of civilisation prevented him from doing to them what they would do to him.