‘Please don’t mention it,’ she said, starting to return some of her books to the briefcase. I picked one of them up and glanced at it.

‘You know, I’d be interested to hear your answer. Can I buy you a drink?’

She looked at her watch. ‘Yes,’ she smiled. ‘I’d like that.’

Die Letze Instanz, at the end of Klosterstrasse on the old city wall, was a local bar much favoured by bulls from the Alex and court officials from the nearby court of last instance, from which the place took its name.

Inside it was all dark-brown wood-panelled walls and flagged floors. Near the bar, with its great draught pump of yellow ceramic, on top of which stood the figure of a seventeenth-century soldier, was a large seat made of green, brown and yellow tiles, all with moulded figures and heads. It had the look of a very cold and uncomfortable throne, and on it sat the bar’s owner, Warnstorff, a pale-skinned, dark-haired man wearing a collarless shirt and a capacious leather apron that was also his bag of change. When we arrived he greeted me warmly and showed us to a quiet table in the back, where he brought us a couple of beers. At another table a man was dealing vigorously with the biggest piece of pig’s knuckle either of us had ever seen.

‘Are you hungry?’ I asked her.

‘Not now I’ve seen him,’ she said.

‘Yes, I know what you mean. It does put you off rather, doesn’t it? You’d think he was trying to win the Iron Cross the way he’s battling that joint.’

She smiled, and we were silent for a moment. Eventually she said, ‘Do you think there’s going to be a war?’

I stared into the top of my beer as if expecting the answer to float to the surface. I shrugged and shook my head.

‘I haven’t really been keeping that close an eye on things lately,’ I said, and explained about Bruno Stahlecker and my return to Kripo. ‘But shouldn’t I be asking you? As the expert on criminal psychology you should have a better appreciation of the Fuhrer’s mind than most people. Would you say his behaviour was compulsive or irresistible within the definition of Paragraph Fifty-one of the Criminal Code?’

It was her turn to search for inspiration in a glass of beer.

‘We don’t really know each other well enough for this kind of conversation, do we?’ she said.

‘I suppose not.’

‘I will say this, though,’ she said lowering her voice. ‘Have you ever read Mein Kampf?’

‘That funny old book they give free to all newlyweds? It’s the best reason to stay single I can think of.’