‘Bernhard, your guess is as good as mine. You could chase him from Pontius to Pilate and still not find him.’ She shrugged and shook her head. ‘If he’s broke he’ll be somewhere like the X Bar, or the Rucker. If he’s got any mouse in his pocket he’ll be trying to nudge a bit of plum at the Femina or the Café Casanova.’ I started down the stairs. ‘And if he’s not at any of those places then he’ll be at the racetrack.’ She followed me out onto the landing and down some of the steps. I got into my car with a sigh of relief. It’s always difficult getting away from a snapper. They never like to see trade walking out of the door.

I don’t have much faith in experts; or, for that matter, in the statements of witnesses. Over the years I’ve come to belong to the school of detection that favours good, old-fashioned, circumstantial evidence of the kind that says a fellow did it because he was the type who’d do that sort of thing anyway. That, and information received.

Keeping a tenor like Neumann is something that requires trust and patience; and just as the first of these does not come naturally to Neumann, so the second does not come naturally to me: but only where he is concerned. Neumann is the best informer I’ve ever had, and his tips are usually accurate. There were no lengths to which I would not go to protect him. On the other hand, it does not follow that you can rely on him. Like all informers he would sell his own sister’s plum. You get one to trust you, that’s the hard bit; but you could no more trust one yourself than I could win the Sierstorpff Stakes at the Hoppegarten.

I started at the X Bar, an illegal jazz club where the band were sandwiching American hits between the opening and closing chords of whatever innocuous and culturally acceptable Aryan number took their fancy; and they did it well enough not to trouble any Nazi’s conscience regarding so-called inferior music.

In spite of his occasionally strange behaviour, Neumann was one of the most nondescript, anonymous-looking people I had ever seen. It was what made him such an excellent informer. You had to look hard to see him, but that particular night, there was no sign of him at the X. Nor at the Allaverdi, nor the Rucker Bar in the rough end of the red-light district.