‘Well, I have read it. And one of the things I noticed was that there is one passage, as long as seven pages, in which Hitler makes repeated references to venereal disease and its effects. Indeed, he actually says that the elimination of venereal disease is The Task that faces the German nation.’

‘My God, are you saying that he’s syphilitic?’

‘I’m not saying anything. I’m just telling you what is written in the Führer’s great book.’

‘But the book’s been around since the mid-twenties. If he’s had a hot tail since then his syphilis would have to be tertiary.’

‘It might interest you to know,’ she said, ‘that many of Josef Kahn’s fellow inmates at the Herzeberge Asylum are those whose organic dementia is a direct result of their syphilis. Contradictory statements can be made and accepted. The mood varies between euphoria and apathy, and there is general emotional instability. The classic type is characterized by a demented euphoria, delusions of grandeur and bouts of extreme paranoia.’

‘Christ, the only thing you left out was the crazy moustache,’ I said. I lit a cigarette and puffed at it dismally. ‘For God’s sake change the subject. Let’s talk about something cheerful, like our mass-murdering friend. Do you know, I’m beginning to see his point, I really am. I mean, these are tomorrow’s young mothers he’s killing. More childbearing machines to produce new Party recruits. Me, I’m all for these by-products of the asphalt civilization they’re always on about — the childless families with eugenically dud women, at least until we’ve got rid of this regime of rubber truncheons. What’s one more psychopath among so many?’

‘You say more than you know,’ she said. ‘We’re all of us capable of cruelty. Every one of us is a latent criminal. Life is just a battle to maintain a civilized skin. Many sadistic killers find that it’s only occasionally that it comes off. Peter Kurten for example. He was apparently a man of such a kindly disposition that nobody who knew him could believe that he was capable of such horrific crimes as he committed.’

She rummaged in her briefcase again and, having wiped the table, she laid a thin blue book between our two glasses.

‘This book is by Carl Berg, a forensic pathologist who had the opportunity of studying Kurten at length following his arrest. I’ve met Berg and respect his work. He founded the Diisseldorf Institute of Legal and Social Medicine, and for a while he was the medico-legal officer of the Düsseldorf Criminal Court. This book, The Sadist, is probably one of the best accounts of the mind of the murderer that has ever been written. You can borrow it if you like.’

‘Thanks, I will.’