The sensible thing would have been to walk back to her and wait till the back-up team was in place. But by then Mann could have left the barge. Or his crewmen could have returned. And Tony was in no mood to be drawn by the sensible option.

He couldn’t resist the sense that he was fated to be in the right place when opportunity opened up before him. He understood the risks, but he no longer felt sufficiently attached to the idea of living to care either way. His guilt over Carol was a maggot in his heart that would only grow fatter with time. He wasn’t sure that was something he could live with. If it was all going to end here, then so be it.

‘I’m sorry, Marijke, I can’t wait. I’m going in. Fingers crossed.’ Tony closed his eyes for a moment, breathing deeply. His body felt as taut as the bonds Krasic had fastened around him. There was no point in being afraid now. He needed all his concentration for Mann.

He stepped on to the gangplank of the Wilhelmina Rosen then called out. ‘Hello? May I come on board?’ He knew there were rules of courtesy about approaching a boat that was also a home and he didn’t want to set Mann’s alarm bells ringing too early.

There was no reply, although lights showed in the wheelhouse and in the cabin below. He moved closer to the deck and called out again. This time, a head appeared at the door of the wheelhouse. It was the young man with the ponytail that he’d seen previously at Koblenz, his face screwed up as he tried to identify the figure silhouetted against the quayside lights. Tony switched to German. ‘Can I come aboard?’ he asked.

‘Who are you?’ the man he assumed to be Wilhelm Mann said.

‘I’m looking for Wilhelm Mann.’

‘I’m Willi Mann. What do you want with me?’

‘Can we talk inside? It’s a private matter,’ Tony said, trying to look innocuous, arms loose by his sides in an unthreatening posture. This was the key moment; it could all be lost now with a tiny nuance that made Mann suspicious.

Mann frowned. ‘What sort of private matter?’

‘About your grandfather.’ Tony took another step forward, a relaxed move calculated to make him appear like a man with only the most casual of intentions.

Mann looked startled. ‘I saw you at Koblenz. Are you following me? What do you want with me?’

‘Just to talk. May I?’ Tony carried on to the end of the gangplank, acting as if it was the most natural thing in the world.

‘I suppose so. Come into the wheelhouse,’ Mann said grudgingly.