‘A couple of years after we married, we moved to a beautiful apartment in Charlottenburg. I became very friendly with a Jewish family in an apartment below us – the Goldmanns. I was especially close to their daughter Esther, who was the same age as me. It was around this time that life became intolerable for Jews in Berlin. The laws being passed made their lives unbearable in almost every respect. Esther’s father was a doctor and lost his job at the Charité hospital, and would you believe it, their beloved dog was taken from them because a law was passed forbidding Jews from owning pets. They could only shop at certain times, they couldn’t own a radio, so many petty things – it was awful. Karl-Heinz thought this was hilarious. He was always rude to them, and when he was around, Esther kept out of the way.

‘Eventually the Goldmanns fled Germany – they went to Belgium as far as I know; I’ve never heard from Esther since they left. Because they left so quickly, most of their possessions remained in their apartment. Karl-Heinz arranged to have the pick of what they owned, so our apartment is stuffed with their silverware, their dinner service, a beautiful dining table and chairs – even paintings. I’m ashamed of this, of course, but I’ve decided to take the view that I’m looking after everything until the family return after the war.

‘As time has gone on, Karl-Heinz has given me every reason to hate him. He boasts about the role he’s played in murdering Jews. I can’t say too much, but I even have evidence of the dreadful things he’s done. He actually seems to believe this impresses me. It has had the opposite effect. I thought about escaping, but where could I go? Then in late 1940 I met an American journalist in Berlin. He was someone I could instinctively trust. I told him I was opposed to the Nazis and wished to help the British. Through him I made contact with the right people in London, and here we are.

‘As far as Karl-Heinz is concerned, I’m a loyal wife and a devoted Nazi and I play up to that role. It’s the perfect cover. Being married to an SS general is like being a member of the aristocracy. Finish the potato salad, there’s only a little left.’

She began to clear the plates and Prince helped her carry them into the kitchen. She made a pot of coffee and they went into the lounge.

‘It’s real coffee, none of that ersatz rubbish: this is what happens when you marry into the SS. Now then, you haven’t come here just to drink decent coffee, have you?’