‘Because they have long memories,’ said Harris. ‘The Stasi funded terror groups in West Germany – the Red Army Faction, the Baaders – when it suited them to have bombs going off and executives being kidnapped. The Reds, with Stasi money, helped Black September plan the attack on the Olympic Village in Munich in 1972 that left eleven Israelis dead. Buchner, the Stasi who murdered Annie Houseman, was believed to be one of the the bagmen for the RAF. Seventeen years or so later, when the opportunity for payback arose, the Israelis took it. If I remember right, they sent us a couple of cases of Judean wine as a token of appreciation. But then, those were more civilized times.’

‘And who do you work for,’ said Louis, ‘or is it impolite to ask?’

‘Officially, I’m retired.’

‘Unofficially?’

‘I help out, on occasion.’

‘So, start helping.’

Harris smiled.

‘The Vuksans and their people haven’t used any of their known passports – we’re on top of those, so I’m certain on that front – which means they’re either still in Europe or they’ve acquired new identities. If it’s the latter, they did so through Anton Frend. He’s not a passport broker, but he has access to individuals who specialize in that area. You know about Nikola Musulin?’

‘I heard he got blown up by a table,’ said Louis.

‘Apparently they’re still searching for his head,’ said Harris. ‘The family is reluctant to bury him without it.’

‘Funny how sentimental people can be.’

‘Isn’t it? Thanks to the elimination of Musulin, the Vuksans have been forced into hiding. But if they can stay alive for long enough, they may be able to cut a deal and return to Serbia.’

‘Cut a deal with whom, Musulin’s successor?’

‘Nominally with his successor, but actually with whichever branch of the Serbian political and judicial establishment signed off on Musulin’s assassination. In the meantime, the Vuksans will soon be hemorrhaging money, if they aren’t already, because you can be sure that someone in Belgrade is going after their assets in order to push them further into a corner. Frend almost certainly has access to a slush fund, but it’s unlikely to contain enough to support the Vuksans in a lifetime of exile.’

‘So Frend is the key,’ said Louis.

‘A very crooked key, and one that won’t easily be turned. If you try by force, you’ll alert the Vuksans. They’ll have set up a series of tripwires: calls at strictly scheduled times, code words, warning signs. The moment Frend fails to follow whatever routines they’ve established, they’ll know he’s been compromised.’

‘Which doesn’t help me.’

‘No, but some other information might,’ said Harris. ‘I know Ross gave you a dossier on Frend. Did you notice that he has a daughter?’

‘Pia. She’s in London, and also a lawyer. Must be a fault in the genes.’