Pfaus was on time and waiting in the hotel lobby. He led the way into the street and across two blocks to the main doorway of the Berlin Kriminalpolizei, a featureless grey building that might have housed any government department. It was distinguished only by the presence of a uniformed police officer at the door with a spiked helmet and a heavy rifle on his shoulder.

‘We have a room with a special one-way window that we can use for your questioning tomorrow,’ Pfaus told him as he led the way down steps to the basement and then along a corridor, bright with electrical globes. ‘So if you wish I can monitor your interview without the prisoner’s knowledge. It can be helpful.’

There were perhaps twenty cells along the corridor. Most of the heavy wooden doors, reinforced with steel spars, were ajar. Swallow could see that the cells were surprisingly spacious and adequately furnished, in contrast with the dungeon-like spaces in which prisoners were held at Exchange Court.

‘A quiet night,’ Pfaus said ruefully. ‘Not too many customers, as you can see.’

He stopped outside one of the few closed doors, drew a brass key from his pocket and inserted it into the lock.

‘Your man is in here. I’ll be waiting here until you are finished. Leave the door open and call if you need me.’

He turned the key, pushed the door and gestured Swallow to step inside.

The cell was pleasantly warm. The man sitting at the wooden table reading a newspaper looked older than his twenty-four years, but he seemed relaxed. An empty dinner plate with the bones of what looked like a couple of lamb chops lay on the table. He looked up with surprise when Swallow entered.

‘Michael James Carmody?’ Swallow asked unnecessarily.

The prisoner nodded.

‘I’m Carmody. And who are you? You sound Irish?’

Stepping closer, Swallow could see that the newspaper was the London Daily Sketch. Carmody was clean-shaven apart from a thin moustache and neatly tended side-locks. He seemed well nourished, and was of average height and build. His hair was dark, oiled and perfectly parted. Michael James Carmody presented himself well, Swallow noted silently.

‘You’re right. I’m Swallow. Detective Inspector, G-Division at Dublin Castle.’

Carmody’s eyes widened. He rose slowly from the chair, dropping the newspaper to the table.

‘From Dublin? Are you serious? Did you say your name is Swalla’?’

‘Sure. Don’t doubt me. Do you want to see my warrant card?’

Carmody shook his head. His expression remained fixed in astonishment.

‘No need, mister Swalla’. I’d know a bleedin’ G-man anywhere.’ He grimaced. ‘Sorry. I didn’t mean any offence. But what are you doin’ here? What d’you want wi’ me?’

‘Sit down there.’

Swallow gestured to the bunk at the wall. Carmody moved across the cell as Swallow took the vacant chair.

‘You’re a long way from home, Michael. And you’re in a bit of trouble.’