‘Sorry,’ I said, ‘but that’s your job. All I had to do was find our aristocratic friend, and that’s as far as it goes. Tell your boss he’ll be receiving my account in the post.’

‘Thanks a lot, Gunther,’ said Rienacker, sounding less than pleased. ‘You’ve got -’ I cut across him with a curt goodbye, and hung up.

I left Inge the keys to the car, telling her to meet me in the street outside Haupthändler’s beach house at 4.30 that afternoon. I was intending to take the special S-Bahn to the Reich Sports Field via the Zoo Station; but first, and so that I could be sure of not being followed, I chose a particularly circuitous route to get to the station. I walked quickly up Königstrasse and caught a number two tram to Spittel Market where I strolled twice around the Spindler Brunnen Fountain before getting onto the U-Bahn. I rode one stop to Friedrichstrasse, where I left the U-Bahn and returned once more to street level. During business hours Friedrichstrasse has the densest traffic in Berlin, when the air tastes like pencil shavings. Dodging umbrellas and Americans standing huddled over their Baedekers, and narrowly missing being run over by a Rudesdorfer Peppermint van, I crossed Tauberstrasse and Jagerstrasse, passing the Kaiser Hotel and the head office of the Six Steel Works. Then, continuing up towards Unter den Linden, I squeezed between some traffic on Französische Strasse and, on the corner of Behrenstrasse, ducked into the Kaiser Gallery. This is an arcade of expensive shops of the sort that are much patronized by tourists and it leads onto Unter den Linden at a spot next to the Hotel Westminster, where many of them stay. If you are on foot it has always been a good place to shake a tail for good. Emerging on to Unter den Linden, I crossed over the road and rode a cab to the Zoo Station, where I caught the special train to the Reich Sports Field.

The two-storey-high stadium looked smaller than I had expected, and I wondered how all the people milling around its perimeter would ever fit in. It was only after I had gone in that I realized that it was actually bigger on the inside than on the outside, and this by virtue of an arena that was several metres below ground level.