‘You have my word. I’ll give her every chance I can. But I have to tell you: right now it looks as though she is in it up to her hatband. I believe that she’s planning to go abroad tonight, so you’d better start talking. There’s not much time.’

For a moment Marlene chewed her lip thoughtfully, her eyes gazing emptily at the hurdlers as they came up to the starting line. She remained oblivious of the buzz of excitement in the crowd that gave way to silence as the starter raised his pistol. As he fired she began to tell me what she knew.

‘Well, for a start there’s her name: it’s not Eva. That was Paul’s name for her. He was always doing that, giving people new names. He liked Aryan names, like Siegfried, and Brünhilde. Eva’s real name was Hannah, Hannah Roedl, but Paul said that Hannah was a Jewish name, and that he would always call her Eva.’

The crowd gave a great roar as the American won the first heat of the hurdles.

‘Paul was unhappy with his wife, but he never told me why. He and I were good friends, and he confided in me a great deal, but I never heard him speak about his wife. One night he took me to a gaming club, and it was there that I ran across Eva. She was working there as a croupier. I hadn’t seen her in months. We first met working for the Revenue. She was very good with figures. I suppose that’s why she became a croupier in the first place. Twice the pay, and the chance to meet some interesting people.’

I raised my eyebrows at that one: I, for one, have never found the people who gamble in casinos to be anything less than dull; but I said nothing, not wishing to cut her thread.

‘Anyway, I introduced her to Paul, and you could see they were attracted. Paul was a handsome man, and Eva was just as good-looking, a real beauty. A month later I met her again and she told me that she and Paul were having an affair. At first I was shocked; and then I thought it was really none of my business. For a while — maybe as long as six months - they were seeing quite a lot of each other. And then Paul was killed. The diary should provide you with dates and all that sort of thing.’

I opened the diary and turned to the date of Paul’s murder. I read the entries written on the page.