I spent the rest of that afternoon reading Gestapo reports on Streicher and his Der Stürmer associates: of the Gauleiter’s affair with one Anni Seitz, and others, which he conducted in secret from his wife Kunigunde; of his son Lothar’s affair with an English girl called Mitford who was of noble birth; of Stürmer editor Ernst Hiemer’s homosexuality; of Stürmer cartoonist Philippe Rupprecht’s illegal activities after the war in Argentina; and of how the Stürmer team of writers included a man called Fritz Brand, who was really a Jew by the name of Jonas Wolk.

These reports made fascinating, salacious reading, of the sort that would no doubt have appealed to Der Stürmer’s own following, but they didn’t bring me any nearer to establishing a connection between Streicher and the murders.

Sievers called back at around five, and said that Vogelmann’s advertising was costing something like three or four hundred marks a month.

‘When did he start spending that kind of mouse?’

‘Since the beginning of July. Only he’s not spending it, Bernie.’

‘Don’t tell me he’s getting it for nothing.’

‘No, somebody else is picking up the bill.’

‘Oh? Who?’

‘Well that’s the funny thing, Bernie. Can you think of any reason why the Lange Publishing Company should be paying for a private investigator’s advertising campaign?’

‘Are you sure about that?’

‘Absolutely.’

‘That’s very interesting, Alex. I owe you one.’

‘Just make sure that if you ever decide to do some advertising it’s me you speak to first, all right?’

‘You bet.’

I put down the receiver and opened my diary. My account for work done on Frau Gertrude Lange’s behalf was at least a week overdue. Glancing at my watch I thought I could just about beat the westbound traffic.

They had the painters in at the house in Herbertstrasse when I called, and Frau Lange’s black maid complained bitterly about people coming and going all the time so that she was never off her feet. You wouldn’t have thought it to look at her. She was even fatter than I remembered.

‘You’ll have to wait here in the hall while I go and see if she’s available,’ she told me. ‘Everywhere else is being decorated. Don’t touch anything, mind.’ She flinched as an enormous crash echoed through the house and, mumbling about men with dirty overalls disrupting the place, she went off in search of her mistress, leaving me to tap my heels on the marble floor.