Fabel read through some of the file. It was filled with horror. Scores of murders initiated by Vitrenko across Central Asia and Europe, ranging from simple assassinations to killings of spectacular cruelty, intended to warn others of the price of crossing him. There was a detailed account of Vitrenko’s activities in Hamburg, including the attack on Maria Klee. There were details of the mass murder that Maria’s notes had referred to: thirty illegal migrants burned to death in a container lorry on Ukraine–Poland border. Fabel read about how a Georgian crime boss had refused Vitrenko’s offer of partnership, saying that his only partners would be his three sons when they were older. Vitrenko had sent the Georgian three packages, all arriving on Father’s Day, each containing a head. There was an account of how a beautiful Ukrainian girl forced into working as a high-class call-girl had tried to break free from Vitrenko’s grasp by contacting the Berlin police. She had been found tied to a chair, facing a full-length mirror. She had died from asphyxiation: her airways inflamed as a result of the sulphuric acid that had been thrown into her face. It was unlikely that she would have been able to see much of her own reflection. But she would have seen enough, thought Fabel, to satisfy Vitrenko. There was the assassination of a Ukrainian-Jewish crime boss in Israel that had Vitrenko written all over it. Fabel shook his head in admiration of Maria as he read. She had mentioned all of these in her notes. Without the resources of the BKA Federal Crime Bureau, she had been able to read Vitrenko’s hand in far-flung and seemingly unconnected incidents.

‘You won’t be surprised by any of this, I suppose …’ said Wagner. The file had included an account of how Vitrenko had murdered his own father; and the fact that Fabel had been a witness to it.

‘We’ve got to get Maria out of Cologne,’ Fabel said without looking up from the file. ‘If Vitrenko gets wind of the fact that she’s got a personal crusade going against him, he will make a point of amusing himself with her death.’

‘I agree, Jan, but the first priority has to be nailing Vitrenko. Maria Klee has got herself into this situation by her own actions.’

‘For which she is not entirely responsible …’ Fabel turned over another page and was faced with photographs of even more victims. He looked up and checked that none of the hotel guests was near enough to see the horror in his hands. ‘What’s this?’