Lord Beaverbrook was not alone when I entered. He was surrounded by the other members of his party: the novelist Arnold Bennett, whom I described in my diary at the time as “sardonic, silent and sallow”; Sunday Express columnist, Lord Castlerosse, “fat, flushed and chortling, a vast cigar sticking out under his arched Edwardian nose”; Mrs. Venetia Montagu, “gracious, erect and smiling”; and Lady Diana Cooper, “brilliant, brittle and blonde, with the palest watery blue eyes.”

They all called Lord Beaverbrook ‘Max.’ I gathered they had come to Berlin in connection with some film which Arnold Bennett was to write, Lady Diana was to star in, and Lord Beaverbrook would finance. I answered telephone calls, took messages in German, replied to questions about Berlin night life. I listened in awe as Lord Beaverbrook, talking to his managers in London, made lightning calculations in his head about the price of the newsprint he was ordering. I ran errands.

For Bennett I went out and bought a stack of the homosexual and nudist magazines I had told him about. No sooner had I given them to him than Lord Castlerosse also wanted a set. I could see wonder about me in the eyes of the woman at the news stand on the Potsdamerplatz, as she sold me the second lot. When I called for the third which Lord Beaverbrook then ordered all her doubts about me had been dispersed. She was certain now of my category.

‘If young girls might always choose their own husbands, we should have the best families intermarry with coachmen and grooms; and young heiresses would throw themselves away upon the first wild young fellows, whose promising outsides and assurance make them set up for fortunes, though all their stock consists in impudence.’ Cervantes, Don Quixote

Germany was the home of the fantastic and the improbable in these golden twenties. What could have been more improbable than that Princess Victoria Schaumburg-Lippe, sister of the ex-Kaiser and granddaughter of Queen Victoria, should marry a penniless young Russian waiter, and live with him as Herr and Frau Zoubkov in Bonn’s stately Schaumburg Palace – today the official residence of the German Federal Chancellor? The Zoubkovs and a train of the ex-waiter’s Russian friends caroused in the palace for just eighteen months. Then the Princess went bankrupt. Zoubkov himself died of a heart attack not long after while touring with a circus freak show, in which he was exhibited as the Kaiser’s brother-in-law.

And where in the world was there a more fantastic murderer than Düsseldorf’s Peter Kürten who stabbed, strangled, and hammered people to death for pleasure and publicity? Kürten sent postcards to the newspapers with maps indicating where corpses could be found of victims of his, who had not even been missed.

I travelled down to Düsseldorf and managed to make friends with Busdorf and Gennath, the two Berlin detectives hunting the Düsseldorf vampire, as I had garishly christened him. And I scored a scoop by being there when the digging party commanded by the foxy faced ex-gamekeeper, Detective-Commissar Busdorf, unearthed first a toe, then a whole corpse of the murdered maidservant, Maria Hahn, at the exact spot which the vampire had indicated. I looked around the crowd watching the digging and wondered which of them was the murderer. For Busdorf had told me he felt certain he would be there among the onlookers.

Then, when the police seemed to have given up the hunt for him as hopeless, and the story of the Düsseldorf vampire had disappeared from the front pages of the world, Kürten gave himself up. But even this he did in a specially dramatic, headline-catching way. He told his wife where he would be at a certain time, and instructed her to inform the police, so that she might collect the reward for his capture.

I was there for his trial in what used to be the riding school of one of the Kaiser’s crack cavalry regiments in Düsseldorf. After seeing Kürten in the dock I could not blame anyone for not having suspected him of being the maniac murderer. Neither the police nor the victims who walked and talked with him before he struck them down. For Kürten with his square head and unaggressive features looked just like any other of the Rhineland’s hundreds of thousands of clerks and tradesmen. The only thing about him that was at all remarkable was the white waxy tip to his stub nose which was otherwise as red as a rose. But no-one had ever reported that. For no-one had ever seen him murder and lived.

Kürten spoke clearly and articulately. As he described each of the twenty-eight murders to which he confessed, he did so with the lurid lyricism of a thriller-writer, savouring once more in closest, nauseating detail the ecstasy of the kill.

On one occasion the excitement of reminiscence, and its effect on the court audience, became so immediate that Kürten gasped and fell silent, ducking down in his grey prisoner’s box while the court and we reporters in the press gallery held our breath in embarrassment until his crisis was over.

Kürten was guillotined in Cologne. Within seconds of his head falling into the executioner’s basket, it was being rushed to a waiting aircraft which flew it to the German-Russian brain institute at Buch near Berlin. There the Kürten brain was carefully extracted from the skull, and sliced into millions of diaphanous segments by the brain scientist – just as they had dissected Lenin’s brain and hundreds of others.

The scientists told me they did this to help them in exploring and charting the human brain. The were trying to discover what fields and sectors in Kürten’s brain showed the abnormality that made him do what he did.