‘Here, have some good Prussian schnapps as a welcome. Protection or observation? Both, of course. We can’t allow an English detective to wander across the country as he pleases, can we?’

Swallow drank from the flask. The fiery schnapps caught at the back of his throat.

‘I’m not English; I’m Irish.’

Pfaus downed a long swallow from the schnapps and handed the flask to Swallow again.

‘English, Irish . . . no difference.’ He chuckled. ‘My colonel distrusts all foreigners. When he knew that I had invited you to come to Berlin he told me you would be my responsibility. Anyway, you work for the Queen of England, yes?’

‘Actually she’s the Queen of a united kingdom. Ireland is one of four countries in that kingdom,’ Swallow explained patiently. ‘She’s also Empress of India, although I suppose that isn’t very relevant to my business here.’

Pfaus chuckled again as Swallow knocked back another draught of schnapps.

‘You could be a spy, my colonel thinks, so I was not to reveal myself any sooner than was necessary. Are you a spy, Mr Swallow?’

Now Swallow grinned.

‘I’d be called worse by some of my own countrymen. No, Johann, Kapitän Pfaus, I’m just a policeman trying to solve a brutal crime that took place in my city. And I’m hoping that your . . . guest, as you call him, Mr Michael James Carmody, the man you told me about in your telegram, might be able to help me.’

‘Tell me about the crime.’

‘Murder. A young girl of eighteen years named Alice Flannery, beaten to death as she walked home at night from her place of employment two months ago. She was a waitress in a restaurant called the New Vienna. Owned and operated by a countryman of yours, as it happens.’

‘You take very seriously the murder of a waitress? Is that usual in your country?’

It was an extraordinary question, Swallow thought. Yet, he realised, the murder of Alice Flannery was not a matter of great import to his own masters in the Upper Yard of Dublin Castle. Perhaps in Germany there was more honesty about what was important and what was not.

‘Well,’ he answered slowly, ‘it may not be important to everyone. But it’s important to me and to my colleagues in the police. And it may be linked to other crimes as well.’

‘I think I understand,’ Pfaus said. ‘And this man, Carmody, is he a suspect? He has a record of violence.’

‘Let me put it this way . . . he’s not off the list of possible suspects. He left Dublin immediately after the murder. And as I told you, he worked in the same restaurant as the murder victim.’

Pfaus nodded.

‘It’s far from conclusive, but professionally I’d take the same view. He must at least be a suspect.’

He paused.