The more I discovered about him, the less inclined I was to believe that he was merely working some elaborate confidence trick. Here was a man interested in something else besides money. A man for whom the word ‘fanatic’ did not seem to be inappropriate. Driving back to Steglitz, I passed Rahn’s house on Tiergartenstrasse, and I don’t thnk I would have been surprised to see the Scarlet Woman and the Great Beast of the Apocalypse come flying out the front door.

It was dark by the time we drove to Caspar-Theyss Strasse, which runs just south of Kurfurstendamm, on the edge of Grunewald. It was a quiet street of villas which stop only a little way short of being something more grand, and which are occupied largely by doctors and dentists. Number thirty-three, next to a small cottage-hospital, occupied the corner of Pauls-bornerstrasse, and was opposite a large florist where visitors to the hospital could buy their flowers.

There was a touch of the Gingerbread Man about the queer-looking house to which Rahn had invited us. The basement and ground-floor brickwork was painted brown, and on the first and second floors it was cream-coloured. A sep-tagonally shaped tower occupied the east side of the house, a timbered loggia surmounted by a balcony the centre portion, and on the west side, a moss-covered wooden gable overhung a couple of porthole windows.

‘I hope you brought a clove of garlic with you,’ I told Hildegard as I parked the car. I could see she didn’t much care for the look of the place, but she remained obstinately silent, still convinced that everything was on the level.

We walked up to a wrought-iron gate that had been fashioned with a variety of zodiacal symbols, and I wondered what the two S S men standing underneath one of the garden’s many spruce trees and smoking cigarettes made of it. This thought occupied me for only a second before I moved on to the more challenging question of what they and the several Party staff cars parked on the pavement were doing there.

Otto Rahn answered the door, greeting us with sympathetic warmth, and directed us into a cloakroom where he relieved us of our coats.

‘Before we go in,’ he said, ‘I should explain that there are a number of other people here for this seance. Herr Weisthor’s prowess as a clairvoyant has made him Germany’s most important sage. I think I mentioned that a number of leading Party members are sympathetic to Herr Weisthor’s work – inc-dentally, this is his home – and so apart from Herr Vogelmann and myself, one of the other guests here tonight will probably be familiar to you.’

Hildegard’s jaw dropped. ‘Not the Fuhrer,’ she said.