Maria had to move back to allow Fabel access to the box room. He imagined the door closed behind him and a spanner ratcheted up the claustrophobia in Fabel’s chest a notch. Fabel could see that this was more than a space allocated for a special purpose. This was another dimension: a world away from the world outside. This was where MacSwain would sit, the closed box-room door as dense and impenetrable as an iron drawbridge, immersed in a universe of alternative truths and morals and beliefs that had been conjured around him. How much MacSwain had conjured himself, and how much of Vitrenko’s hand could be seen in it, Fabel was unsure.

Something shone bronze-gold in the spotlights. The oval shape of an embossed Kriminalpolizei shield hung by its beaded chain from a panel pin. It was this shield that had been the key to Angelika Blüm’s flat, to her trust; it was this shield that had deceived Blüm into believing that her killer had been Fabel. Maria leaned past her boss and indicated a newspaper cutting that was pinned on top of the layers of others.

‘Christ,’ she muttered, ‘it’s you.’

The article, a year old, had been cut from from the Hamburger Morgenpost. Fabel’s photograph sat at the top of a couple of columns about his arrest of Markus Stümbke. Stümbke had stalked and murdered a female member of the Senate, Lise Kellmann. The article was obviously a follow up to the main story, because it went into greater depth, as the headline promised, about Fabel’s background and history with the Polizei Hamburg. MacSwain had underlined a reference to Fabel’s mixed British-German parentage and the fact that he was occasionally referred to as der englische Kommissar. Fabel scanned the rest of the display. It was almost all devoted to Viking mythology and history. A map of northern Europe showed the routes taken by the Vikings: down the Volga into the heart of the Ukraine, alone the North Sea and Baltic Coasts and, again highlighted in red, the route they took to raid and settle on the coasts of northern Scotland. With that red felt-tipped pen, MacSwain had sewn a thread of spurious personal history; a thin but unbreakable web of perverted justification for his actions.

‘Notice something missing?’ Fabel asked Maria. She nodded.

‘No pictures or details of the victims … no trophies.’

‘Exactly.’

Serial killers habitually sought a ‘relationship’ with those they murdered, even if the first contact had been the act of killing itself. There were no references here. Not to Ursula Kastner, not to Angelika Blüm, not to Tina Kramer. There were no surreptitiously taken photographs of the victims prior to death. There were no articles of clothing. There were no trophies.

‘It’s because he didn’t pick his own victims,’ Fabel said. ‘They were selected for him. The object of MacSwain’s obsession isn’t his victim, it’s the person who is guiding him. His spiritual father: Vitrenko. It’s Vitrenko who fills the gap left by a natural father who didn’t give a shit.’