The quantity of flesh removed may be significant in itself. In each case it has been extremely close to the 0.45 kilogram measure. This equates to one Imperial pound in weight, as used by the British. This is not to say that the killer is a foreign national, more that ‘a pound of flesh’ is intended (as in the Shakespeare play The Merchant of Venice) and therefore is a metaphor for recovering justice from the victims. This could suggest that the killer was known to his victims.

It is clear from the consistency of modus that the perpetrator of the first murder also carried out the second homicide. This, added to the symbolism of the tie left at each scene and the significance of Karneval, and the implied expression of psychosexual hatred of women all point to a serial offender.

Fabel leafed through the file. Weiberfastnacht had another name. Fetter Donnerstag. Fat Thursday. A day devoted to gluttony.

‘No, Herr colleague,’ Fabel said under his breath as he re-examined the scene-of-crime images. ‘Our friend isn’t interested in collecting mementos. He’s hungry. His pound of flesh isn’t a trophy: it’s a meal.’

The phone rang.

10.

They stood and stared at the three clear plastic packages on Anna’s desk: one containing an ancient-looking Walther P4 handgun, the other holding a carrier bag with cash and the third with a large dog-eared book in it. Each of them was sealed and labelled with a blue evidence tag.

‘We found it outside the store,’ said Anna Wolff, indicating the book. She was in charge of the case. ‘Philosophy. That’s what Tschorba studied – at one time, anyway.’

Fabel continued to stare silently at the evidence bags.

Anna ran through what had happened in the convenience store. The Turkish owner had said in his statement that Breidenbach had died bravely; that the young policeman had been determined that the robber would not go out into the street with a handgun. He also stated that he had got the idea to jump Tschorba from Breidenbach, who had told the gunman that he couldn’t take them both. As Timo Tschorba had fired the fatal shots into Breidenbach’s body, the shopkeeper had thrown himself at him. Tschorba was now in the cells, his swollen and bruised face bearing the marks of the encounter with the Turk. Once the shopkeeper had disarmed the junkie, he had rushed over to Breidenbach, but the young policeman was already dead. He admitted that when he had seen that, he had gone back and pistol-whipped Tschorba, who had cried like a child.

‘I can’t believe it,’ said Fabel at last. ‘He was there. I mean Breidenbach. He was there at the Aichinger incident. He was the MEK trooper who came up to the apartment with me.’ He shook his head mournfully. ‘I behaved like an arsehole … I treated Breidenbach as if he were less of a policeman than me. Just because he was a tactical weapons specialist. I was wrong. He was a police officer first and foremost.’