Each of these strategies had failed. But now the combination of a little blue pill and his experience with Frances had overcome that first objection. The second objection had fallen to the realization that what they had endured together could make them stronger rather than damage their intimacy. And now the distance had been shattered, and the world hadn’t ended.

In all his working life, he had never found it possible to talk openly to another human being about his feelings when confronted with the appalling things one person could do to another. Yet the night before, he’d spilled out the anguish in his heart to Carol without a second thought. Even as he’d spoken, there had been an admonitory voice in the back of his head, warning that he was saying far too much. But he’d ignored it and, instead of revulsion, he’d found compassion. After the horrors of the Nazi records, he’d feared a succession of sleepless nights, afraid to close his eyes because of what dreams could do to him. Somehow Carol had acted as balm, releasing him from the terrible power of his imagination.

For the first time in years, he had something to look forward to beyond the closure of the case that currently occupied his mind. It was a tantalizing prospect. But before then, he had work to do. Tony pushed himself into a sitting position. Something was niggling at the back of his mind and he couldn’t quite put his finger on it. It was something he’d seen or heard in Bremen, a detail that hadn’t seemed relevant at the time but which should mean something to him now. ‘Where are you, Geronimo?’ he said softly. ‘Are you planning the next one? Where is it going to be next? Where is the water going to take you next?

‘Water’s your element, that’s why you drown them. And, somehow, water ties in to what was done to you. Maybe whoever made you their victim also suffered from it. Maybe your father or your grandfather endured the water torture room at Hochenstein. Is this the symbolic connection that establishes your superiority over your victims? A way of asserting that your magic is more powerful than theirs?’ This realization reinforced Tony’s conviction that they were looking for someone with links to the European waterway network. Water was the key, he thought.

Then, because the brain works in ways that nobody comprehends, the thought he had been seeking slipped into the front of his mind. ‘The river,’ he exclaimed. He jumped out of bed, reaching for last night’s crumpled shirt and thrusting his arms into the sleeves. A brief waft of the fragrance of Carol’s hair hit his nostrils and he smiled.

His laptop sat open on the escritoire. He brought it back to life from snooze mode and started to compose an e-mail to Carol, Petra and Marijke.

Good morning, ladies.