Fabel nodded. ‘He is supposedly the head of a Ukrainian crime gang. A new one that is taking over the activities of all others in the city.’

‘Vasyl Vitrenko is – was – a full colonel in the Berkut. Vitrenko has a service record that many admire to the point of adulation. Others see him as a monster. As the Devil. In another place, in another time, I was charged with the responsibility of finding and stopping Vitrenko’s worst excesses. Vitrenko has gathered around him ten of his former subordinate officers – men who served under him in Chechnya or Afghanistan, or both – each of whom has a record of both outstanding bravery and exceptional cruelty. Each of these officers remains fiercely loyal to Vitrenko. What is more, Vitrenko has promised to make them all millionaires. A promise he is already close to fulfilling. One of these officers was a Major Pavlo Klimenko.’

‘So Vitrenko snatched your crooked little scheme away right from under you?’ Fabel gave a bitter laugh.

The Slav’s green eyes glittered in the bleak artificial light of the Portakabin. ‘That is correct, Herr Hauptkommissar. But before you get too smug, I would point out that your government is capable of underhand dealing too. What was the objective of the operation involving the unfortunate Herr Klugmann?’

‘I’m not prepared to discuss that with you.’

‘No? All right, Herr Hauptkommissar. Allow me to answer my own question. You believe that Herr Klugmann was carrying out a surveillance and intelligence-gathering operation on the activities of Vasyl Vitrenko and his crew. Correct?’

Fabel shrugged and nodded.

‘Not so, Herr Fabel. Herr Klugmann had only one objective: to contact and negotiate with Vasyl Vitrenko. Klugmann was an operative of the BND and he had a deal to offer. Your government, in the full knowledge of Vitrenko’s murderous past and his criminal present, is prepared to offer him immunity from prosecution and a lucrative deal.’

‘Why on earth would the German federal government do business with a known major criminal?’

‘Because of September 11th, 2001.’

‘What?’

‘Eight of the ten suicide bombers that carried out the attack on the World Trade Center in New York lived in or passed through Hamburg immediately before the attack. It has been a matter of considerable embarrassment both to the city and national governments. In short, you Germans would do anything to help the Americans. And the Americans need all the help they can get. Vasyl Vitrenko is a highly intelligent and educated man; he is also a leading expert on Afghanistan and Islamic terrorism. The CIA have made it clear to BND that they would be greatly obliged if they could land Vitrenko for them. Your colleague, Klugmann, was briefed to begin negotiations; the apartment in which the girl was killed was set up as the venue for those negotiations.’

Fabel looked hard at the Slav, and then at the girl with the blonde hair. It wouldn’t be the first time expedience and the imperative of ‘the greater good’ had bulldozed over the rule of law. The Slav watched Fabel impassively, giving him the time to consider his response. Eventually Fabel said: ‘But the only contact Klugmann had with the new Ukrainian outfit was someone called Vadim. Other than that there was no contact.’