Tony understood that psychological state only too well. He had spent his own adult life feeling out of place in the world. He had lived with a sense of worth-lessness that made it impossible to love, for loving carried implicit within it the conviction that one deserved to be loved in return. And he had never been able to believe that about himself. He had constructed his own series of masks, an empathetic sequence of facades that allowed him to blend in. Passing for human. If his circumstances had been different, he had always believed he might have ended up a predator himself, instead of a hunter. It was that awareness that underpinned all he did. It made him supremely good at unpicking the minds of the deranged and depraved.

It also made him supremely bad at forging relationships that penetrated beyond the superficial. Mostly, he had accepted that as a price worth paying for having in his grasp so useful and beneficial a skill. Carol Jordan was the only person who had ever made him feel that this was just another lie he told himself.

He knew he didn’t deserve her. But the harder he tried to pull away from her, the stronger the tug towards her grew. One of these days he was going to have to take the chance of losing what he did best in the attempt to become what he had never understood how to be. Being a man instead of acting a part might alter him so profoundly that he could no longer navigate the labyrinth of messy minds.

But that was for another day. Tony gave himself a mental shake and set about reading the trail that Geronimo had left behind him. He began to plough through the contents of the crime files, taking notes as he went. The material from Heidelberg and Leiden was comprehensive, the boxes containing everything from witness statements to crime scene photographs and background reports on the victims. Luckily, the Dutch files had been translated into English for Petra’s benefit, so he had no trouble reading them, apart from the odd awkward rendering. There was almost nothing from Bremen, simply because the investigation was still in the early stages and Petra’s request hadn’t yet borne much fruit.

Petra had made no attempt to engage him in conversation once he began, simply placing a fresh pot of coffee on the dining table where he was working. She poured herself a cup and said, ‘I’m going out soon. I have to keep watch over Carol.’