Gert Jeschonnek was a burly hog of a man, with small piggy eyes and a brown beard cropped close to his sunburned face. He wore a light-grey double-breasted suit that was ten years too young for him, and in the lapel was a Scary Badge. He had March Violet plastered all over him like insect repellent.

‘Herr Gunther,’ he said brightly, and for a moment he was almost standing at attention. Then he crossed the floor to greet me. A purplish butcher’s hand pumped mine own, which showed patches of white when I let it go. He must have had blood like treacle. He smiled a sweet smile and then looked across my shoulder to his anaemic secretary who was about to close the door on us. Jeschonnek said:

‘Helmut. A pot of your best strong coffee please. Two cups, and no delays.’ He spoke quickly and precisely, beating time with his hand like a teacher of elocution. He led me over to the desk, and the ruby, which I figured was there to impress me, in the same way as the copies of Der Stürmer were there to impress his Jewish custom. I pretended to ignore it, but Jeschonnek was not to be denied his little performance. He held the ruby up to the light in his fat fingers, and grinned obscenely.

‘An extremely fine cabochon ruby,’ he said. ‘Like it?’

‘Red isn’t my colour,’ I said. ‘It doesn’t go with my hair.’ He laughed and replaced the ruby on the velvet, which he folded up and returned to his safe. I sat down on a big armchair in front of his desk.

‘I’m looking for a diamond necklace,’ I said. He sat down opposite me.

‘Well, Herr Gunther, I’m the acknowledged expert on diamonds.’ His head gave a proud little flourish, like a racehorse, and I caught a powerful whiff of cologne.

‘Is that so?’ I said.

‘I doubt if there’s a man in Berlin who knows as much about diamonds as I do.’ He thrust his stubbly chin at me, as if challenging me to contradict him. I almost threw up.

‘I’m glad to hear it,’ I said. The coffee arrived and Jeschonnek glanced uncomfortably after his secretary as he minced out of the room.

‘I cannot get used to having a male secretary,’ he said. ‘Of course, I can see that the proper place for a woman is in the home, bringing up a family, but I have a great fondness for women, Herr Gunther.’

‘I’d take a partner before I’d take on a male secretary,’ I said. He smiled politely.

‘Now then, I believe you’re in the market for a diamond.’

‘Diamonds,’ I said, correcting him.

‘I see. On their own, or in a setting?’