‘It’s good to see you again, Herr Professor,’ Fabel lied. For Fabel, Dorn, and the feelings he awoke, belonged in the past. Fabel wished he had stayed there. He sat across the desk from Dorn. There was a photograph on the desk: a young woman of about twenty, with a similar porcelain delicacy to her features. Fabel was involuntarily drawn to the picture, amazed at how unfamiliar the face now seemed.

‘I was surprised to find you were here,’ said Fabel.

‘Just two days a week.’ Dorn smiled. ‘Enough for me to qualify as “historian in residence”. It’s a strange concept, having a historian in a prison. But there again this prison has a special history of its own. I divide my time between here and the Neuengamme memorial.’

‘I meant that I’m surprised that you wanted to work with offenders after …’ Fabel found he had started a sentence he didn’t want, or need, to finish. Dorn read his meaning and smiled.

‘It’s actually very rewarding. Some of the inmates have developed a real hunger for history. In a strange way it helps them make sense of their own histories. But I take your meaning. I suppose I did have my own agenda when I applied for the post. I needed to understand, to be around men who kill, I suppose. To … well, to make some kind of sense of what happened.’

‘And has it?’

‘Has becoming a policeman helped you?’

‘I don’t know if that was the reason I became a policeman.’ Again, Fabel lied. They both knew it was the personal history they shared that had led a gifted historian like Fabel to become a murder detective.

Dorn let it go. ‘I wanted to talk to you about this murder you’re investigating,’ he said.

‘Murders,’ corrected Fabel. ‘There’s been another one. The same form of killing as the Kastner girl.’

‘My God, that’s awful. It confirms what I thought. That’s why I wanted to see you.’

‘Go on. Please, Professor.’

Dorn picked up a recent copy of Hamburger Morgenpost. It was open at an article on the Kastner murder.

‘Like you,’ continued Dorn, ‘I have been, well, forced into taking an interest in the psychotic mind. I hate to say it, but, despite its innate destructiveness, there can sometimes be a form of twisted creativity in it.’ He stabbed a finger at the article. ‘I think you have someone very creative as well as very dangerous at work here, Jan. This fellow’s psychosis is certainly very well … informed, I suppose would be the best way of putting it.’

‘What do you mean?’

Dorn laid the paper back on his desk. He held up his hand in a gesture that suggested Fabel should slow down and wait for him to unfold his thesis. It was a gesture with which Fabel had been so accustomed as an eager student.

‘Who are we?’ Dorn asked. ‘What are we? The Germans, I mean.’

Fabel frowned. ‘I don’t understand …’