‘Grete was teaching until 1934 when, like many other women, she lost her job - a casualty of the government’s general discrimination against working women in the employment drive. Meanwhile Paul landed a job at the Ministry of the Interior. Not long afterwards my first wife Lisa died, and Grete became very depressed. She started drinking and staying out late. But just a few weeks ago she seemed her old self again.’ Six regarded his brandy morosely and then threw it back in one gulp. ‘Three nights ago, however, Paul and Grete died in a fire at their home in Lichterfelde-Ost. But before the house caught fire they were each shot, several times, and the safe ransacked.’

‘Any idea what was in the safe?’

‘I told the fellows from Kripo that I had no idea what it contained.’

I read between the lines and said: ‘Which wasn’t quite true, right?’

‘I have no idea as to most of the safe’s contents. There was one item, however, which I did know about and failed to inform them of.’

‘Why did you do that, Herr Six?’

‘Because I would prefer that they didn’t know.’

‘And me?’

‘The item in question affords you with an excellent chance of tracking down the murderer ahead of the police.’

‘And what then?’ I hoped he wasn’t planning some private little execution, because I didn’t feel up to wrestling with my conscience, especially when there was a lot of money involved.

‘Before delivering the murderer into the hands of the authorities you will recover my property. On no account must they get their hands on it.’

‘What exactly are we talking about?’

Six folded his hands thoughtfully, then unfolded them again, and then swathed himself with his arms like a party-girl’s wrap. He looked quizzically at me.

‘Confidentially, of course,’ I growled.

‘Jewels,’ he said. ‘You see, Herr Gunther, my daughter died intestate, and without a will all her property goes to her husband’s estate. Paul did make a will, leaving everything to the Reich.’ He shook his head. ‘Can you believe such stupidity, Herr Gunther? He left everything. Everything. One can hardly credit it.’

‘He was a patriot then.’

Six failed to perceive the irony in my remark. He snorted with derision. ‘My dear Herr Gunther, he was a National Socialist. Those people think that they are the first people ever to love the Fatherland.’ He smiled grimly. ‘I love my country. And there is nobody who gives more than I do. But I simply cannot stand the thought that the Reich is to be enriched even further at my expense. Do you understand me?’

‘I think so.’

‘Not only that, but the jewels were her mother’s, so quite apart from their intrinsic value, which I can tell you is considerable, they are also of some sentimental account.’

‘How much are they worth?’