Heck pushed his face within an inch of Rothstein’s and bared his teeth. ‘You see I have a suspicious mind. It is difficult not to have doubts about people when your family has been wiped from the face of the earth. And you know, Albert Rothstein, your tattooed number looks very fresh and clear. I have seen other Auschwitz tattoos and they are not so neat. There are other things about you, too. The way you hold your cigarette, like a Hollywood movie star. KZ survivors hide their cigarette, cupped in the palm of their hand, because smoking in the camps was punishable by death and they’re still scared. They will always be scared, if they live to be a hundred. Also, you don’t look at other people’s food. But all the survivors do. They can’t take their eyes off someone else’s plate or bowl, especially if they think they have been given a larger ration in the canteen. It’s natural when you have been fed nothing but a half-litre of cabbage water every day for two years.’

‘I have fought against these things, Mo. I am trying hard to get back to normal. I want to rid myself of the nightmares, not keep reliving them.’

Heck ignored his protestations. ‘And then there is my little friend Jerzy. Do you know him, the boy with the camera?’

‘No. I know no little boy.’

‘He knows you. He remembers you from Krakow. He says you weren’t one of the Jews being marched to the transport. He says you were Waffen-SS and you looked very smart in your uniform. He says you smiled at him and gave him a sweet from your pocket, then carried on driving the Jews to their graves.’

Rothstein was sweating now, his eyes swivelling, looking for a way out of this, somewhere to run. But he had already worked out that Mozes Heck was a great deal fitter, faster and stronger than him. There were plenty of people around, but no one who could help him. ‘This is nonsense,’ he said. ‘Utter nonsense. Why would you listen to such things from a stupid boy.’

Heck pushed the muzzle hard into Rothstein’s damp forehead. ‘Take off your shirt and jacket or I will shoot you like a dog.’

The man who called himself Rothstein backed off from the gun, and suddenly twisted into a run, but Heck was much too quick for him and brought him down with a flying tackle to the legs. He pulled the gun back and smacked it hard into Rothstein’s temple with the butt. There was an audible crack and the German flopped forward, stunned by the blow. Heck knelt behind him and dragged off his jacket, then tore the shirt away and grasped his white left arm.

‘What is this, Rothstein?’

He gripped his prey’s head in an armlock.

Rothstein’s mouth was open, his eyes scrunched up. ‘My head,’ he gasped. ‘You hit me.’

‘Did I?’ He smacked him again on the head, this time on the other temple. Then he held the muzzle of the pistol to the second tattoo on his arm. This one was higher up from the tattooed number, near the elbow. There were two letters: AB. ‘This looks like your blood type, Rothstein, or whatever your true name is. Why do you have your blood type tattooed there? As far as I know only the Waffen-SS have their blood group on their arm.’