‘There was a stage when Reinhard was persuaded to be treated for his homosexuality. At first he tried various endocrine preparations, but these proved ineffective. Psychotherapy seemed to offer a better chance of success. I believe several high-ranking Party members, and boys from the Hitler Youth, have undergone the same treatment. Kindermann is a psychotherapist, and Reinhard first became acquainted with him when he entered Kindermann’s clinic in Wannsee seeking a cure. Instead he became intimately involved with Kindermann, who is himself homosexual.’

‘Pardon my ignorance, but what exactly is psychotherapy? I thought that sort of thing was no longer permitted.’

Frau Lange shook her head. ‘I’m not exactly sure. But I think that the emphasis is on treating mental disorders as part of one’s overall physical health. Don’t ask me how that differs from that fellow Freud, except that he’s Jewish, and Kindermann is German. Kindermann’s clinic is strictly Germans only. Wealthy Germans, with drink and drug problems, those for whom the more eccentric end of medicine has some appeal –chiropracty and that sort of thing. Or those just seeking an expensive rest. Kindermann’s patients include the Deputy Führer, Rudolf Hess.’

‘Have you ever met Dr Kindermann?’

‘Once. I didn’t like him. He’s a rather arrogant Austrian.’

‘Aren’t they all?’ I murmured. ‘Think he’d be the type to try a little blackmail? After all, the letters were addressed to him. If it isn’t Kindermann, then it has to be somebody who knows him. Or at least somebody who had the opportunity to steal the letters from him.’

‘I confess that I hadn’t suspected Kindermann for the simple reason that the letters implicate both of them.’ She thought for a moment. ‘I know it sounds silly, but I never gave any thought as to how the letters came to be in somebody else’s possession. But now you come to mention it, I suppose that they must have been stolen. From Kindermann I would think.’

I nodded. ‘All right,’ I said. ‘Now let me ask you a rather more difficult question.’

‘I think I know what you’re going to say, Herr Gunther,’ she said, heaving a great sigh. ‘Have I considered the possibility that my own son might be the culprit?’ She looked at me critically, and added: ‘I wasn’t wrong about you, was I? It’s just the sort of cynical question that I hoped you would ask. Now I know I can trust you.’