Sitting opposite him in the carriage, Michael Carmody slumbered uneasily beside the impassive, helmeted policeman whose left wrist was chained to his right. Even if he was returning to Dublin voluntarily and as a witness, neither Swallow nor Pfaus were taking any chances that he might simply vanish off the train at some point on the journey.

There would be a railway police escort at the Hamburg Hauptbahnhof to see them onto the train for the Hook of Holland. A Dutch escort would take over at the border, Pfaus had explained, and would accompany them as the packet crossed the North Sea to Harwich.

Half a dozen times, as the train plunged through the darkness, Swallow reread the telegram in the weak light, as if somehow he might discover a different, more hopeful interpretation of its stark, ungrammatical wording.

MARIA ADMITTED ROTUNDA

+ CONDITION SERIOUS

+ ESSENTIAL RETURN IMMEDIATELY

+ LAFEYRE

What could possibly have gone wrong, he asked himself repeatedly. Maria was in the Rotunda Lying-In Hospital. That had to mean there was some problem with the baby. Or with Maria. But the specialist at the hospital had said that everything was in order, Maria was healthy, and he could hear the baby’s heart in his stethoscope. ‘Condition serious’, Lafeyre had said. What did that mean? Did ‘serious’ imply a threat to her life? Or the baby’s? Or both? It had to be grave. He would not be recalled from an important investigation for any trivial reason. The only word in the telegram from which he could take comfort was the signoff: ‘Lafeyre’. With Harry engaged, Swallow knew, Maria would get the best possible care and attention.

Pfaus had hurriedly arranged transport from the Kriminalpolizei building when Swallow, now ashen-faced, had handed him the opened telegram in Carmody’s cell. The police sidecar had sped to the Berlin Hauptbahnhof to catch the next train for Hamburg.

‘I shall telegraph your Doctor Lafeyre in Dublin, Joseph,’ Pfaus assured Swallow as he climbed aboard the sidecar. ‘I’ll try to find out what I can and communicate what I learn to my colleagues at Hamburg. When you change trains, be sure to check if there is a message from Kriminalpolizei Berlin.’

But there was no message at Hamburg. The railway policeman shrugged and offered a puzzled apology when the escorting officer queried him. And there was no message at the police post on the wharf at the Hook of Holland. But there were two Dutch police officers to take custody of Swallow’s prisoner from the Prussians.