The dead man was Geert Vranken, aged thirty-nine, born at Dordrecht in the Netherlands, a volunteer railway worker; living at a hostel in Wuhlheide. The face in the photograph was wary-looking, with a cleft chin that was slightly unshaven. The eyebrows were short and the hair thinning to one side. He appeared to be wearing the same thick flannel jacket as the one on the body, and a collarless shirt buttoned up to the neck. Even as we were reading the bare details of Geert Vranken’s shortish life, another policeman was coming up the stairs of Jannowitz Station with what, in the darkness, looked like a small round bag.

‘I found the head, sir,’ reported the policeman. ‘It was on the roof of the Pintsch factory.’ He was holding the head by the ear, which, in the absence of much hair, looked as good a way to carry around a severed head as any you could have thought of. ‘I didn’t like to leave it up there, sir.’

‘No, you were right to bring it along, lad,’ said Sergeant Stumm and, taking hold of the other ear, he laid the dead man’s head carefully on the railway platform so that it was staring up at us.

‘Not a sight you see everyday,’ said Wurth and looked away.

‘You want to get yourself up to Plotzensee,’ I remarked. ‘I hear the falling axe is very busy these days.’

‘That’s him all right,’ said Lehnhoff. ‘The man in the worker’s book. Wouldn’t you say?’

‘I agree,’ I said. ‘And I suppose someone might have tried to rob him. Or else why go through his pockets?’

‘You’re sticking to the theory that this is a murder and not an accident then?’ enquired Lehnhoff.

‘Yes. I am. For that reason.’

Sergeant Stumm tutted loudly and then rubbed his stubbly jaw, which sounded almost as loud. ‘Bad luck for him. But bad luck for the murderer, too.’

‘What do you mean?’ I asked.

‘Well, if he was a foreign worker, I can’t imagine there was much more than fluff in his pockets. It’s a hell of a disappointing thing to kill a man with the intent of robbing him and then find that he had nothing worth stealing. I mean, these poor fellows aren’t exactly well paid, are they?’