Spiedel consulted the file. ‘Just the one, from the Union of Ex-Convicts, a welfare organization we are led to believe, although I have my doubts as to the authenticity of that organization. A man by the name of Kasper Tillessen. He visited Mutschmann on two occasions.’

‘Did Mutschmann have a cellmate?’

‘Yes, he shared with 7888319, Bock, H.J.’ He retrieved another file from the drawer. ‘Hans Jürgen Bock, aged thirty-eight. Convicted of assaulting and maiming a man in the old Steel Workers Union in March 1930, sentenced to six years’ imprisonment.’

‘Do you mean that he was a strike-breaker?’

‘Yes, he was.’

‘You wouldn’t happen to have the particulars of that case, would you?’

Spiedel shook his head. ‘I’m afraid not. The case file has been sent back to Criminal Records at the Alex.’ He paused. ‘Hmm. This might help you, though. On discharge Bock gave the address where he was intending to stay as “Care of Pension Tillessen, Chamissoplatz, Number 17, Kreuzberg’. Not only that but this same Kasper Tillessen paid Bock a visit on behalf of the Union of Ex-Convicts.’ He looked at me vaguely. ‘That’s about it, I’m afraid.’

‘I think I’ve got enough,’ I said brightly. ‘It was kind of you to give me some of your time.’

Spiedel adopted an expression of great sincerity, and with some solemnity he said: ‘Sir, it was my pleasure to help the man who brought Gormann to justice.’

I reckon that in ten years from now, I’ll still be trading off that Gormann business.

When a man’s wife visits him only once in two years’ cement, then she doesn’t bake him a sponge-cake to celebrate his freedom. But it was possible that Mutschmann had seen her after his release, if only to knock the shit out of her, so I decided to check her out anyway. You always eliminate the obvious. That’s fundamental to detection.

Neither Mutschmann nor his wife lived at the address in Cicerostrasse any more. The woman I spoke to there told me that Frau Mutschmann had re-married, and was living in Ohm-strasse on the Siemens housing-estate. I asked her if anyone else had been around looking for her, but she told me that there hadn’t.

It was 7.30 by the time I got to the Siemens housing-estate. There are as many as a thousand houses on it, each of them built of the same whitewashed brick, and providing accommodation for the families of the employees of the Siemens Electrical Company. I couldn’t imagine anything less congenial than living in a house that had all the character of a sugar lump; but I knew that in the Third Reich there were many worse things being done in the name of progress than the homogenizing of workers’ dwellings.