Snow lay here and there, piled in drifts along the railway embankment. The countryside was as flat and featureless as his native Kildare, but the layout of the farmland was different. At home, fields were generally bounded by high ditches. Here, longer and wider strips of land were divided by straight, shallow gullies. The farmhouses were different too. The larger ones were squat and solid with wooden trusses at the gable ends. He thought they lacked the simple Georgian elegance of the two-storeyed dwellings favoured by strong farming families in rural Ireland, but, he reflected, had he been travelling on his own he would have liked to attempt a simple sketch of the structure.

They reached Berlin shortly before five o’clock. Through the frosting windows Swallow could see lines of carriages and cabs, oil lanterns flaring in the early evening darkness, jostling on the cobbled forecourt of the bahnhof.

Two uniformed policemen sprang to a perfectly synchronised salute as they emerged past the ticket barrier. One reached to take Swallow’s suitcase.

‘Guten Abend, Herr Hauptmann. Ihre Anweisungen bitte.’

‘I have arranged accommodation for you at Hotel Bremen, off Wilhelmstrasse,’ Pfaus told Swallow. ‘It’s a good hotel, and it’s just one minute from our headquarters. My men will bring you there now, so you can wash, rest for a while or whatever you wish. Would you like to start your interrogation of the prisoner this evening, or would you prefer to leave it until the morning when you will have slept?’

It would not be clever, Swallow knew, to go straight into an important interrogation directly after a tiring two-day journey. But it might be useful in forming an opinion of his man to see Carmody briefly, perhaps get something of his measure and maybe discomfit him, softening him up for later questioning.

‘I’d be glad to freshen up and rest briefly. Perhaps I might see the prisoner then later in the evening. For perhaps half an hour?’

‘Very well,’ Pfaus nodded. ‘I have to report to my superiors, and I shall meet you at the Hotel Bremen, shall we say at seven o’clock this evening in the lobby, and I will take you to our headquarters. Then afterwards perhaps you would do me the honour of having supper with me and my family at our home. My wife does the best Wiener Schnitzel in Berlin.’

That sounded good, Swallow reckoned.

‘Thank you, Johann; I’ll accept that offer with great pleasure.’

The room on the second floor of the Bremen was small but comfortable, with a high bed on a solid iron frame. But the sheets were fresh linen and the blankets solid, comforting wool. Swallow used the adjacent bathroom with its running water supply to wash the grime of the journey from his body and put on a fresh shirt. He lay down on the narrow bed, closed his eyes and rested until it was time to go downstairs.