He got NCIS to fax him what information they had. Most of it concerned the ‘Tippelzone’, a licensed car park where drivers went for sex. It was worked by foreign prostitutes mainly, most of them lacking work permits, many smuggled in from Eastern Europe. The main gangs seemed to be from former Yugoslavia. NCIS had no names for any of these kidnappers-cum-pimps. There was nothing about prostitutes making the trip from Amsterdam to Britain.

Rebus went into the car park to smoke his second cigarette of the day. There were a couple of other smokers out there, a small brotherhood of social pariahs. Back in the office, the Farmer wanted to know if there was any progress on Lintz.

‘Maybe if I brought him in and slapped him around a bit,’ Rebus suggested.

‘Be serious, will you?’ the Farmer growled, stalking back to his office.

Rebus sat down at his desk and pulled forward a file.

‘Your problem, Inspector,’ Lintz had said to him once, ‘is that you’re afraid of being taken seriously. You want to give people what you think they expect. I mention the Ishtar gate, and you talk of some Hollywood movie. At first I thought this was meant to rouse me to some indiscretion, but now it seems more a game you are playing against yourself.’

Rebus: seated in his usual chair in Lintz’s drawing-room. The view from the window was of Queen Street Gardens. They were kept locked: you had to pay for a key.

‘Do educated people frighten you?’

Rebus looked at the old man. ‘No.’

‘Are you sure? Don’t you perhaps wish you were more like them?’

Lintz grinned, showing small, discoloured teeth. ‘Intellectuals like to see themselves as history’s victims, prejudiced against, arrested for their beliefs, even tortured and murdered. But Karadzic thinks himself an intellectual. The Nazi hierarchy had its thinkers and philosophers. And even in Babylon ...’

Lintz got up, poured himself more tea. Rebus declined a refill.

‘Even in Babylon, Inspector,’ Lintz continued, getting comfortable again, ‘with its opulence and its artistry, with its enlightened king ... do you know what they did? Nebuchadnezzar held the Jews captive for seventy years. This splendid, awe-inspiring civilisation ... Do you begin to see the madness, Inspector, the flaws that run so deep in us?’

‘Maybe I need glasses.’

Lintz threw his cup across the room. ‘You need to listen and to learn! You need to understand!’ The cup and saucer lay on the carpet, still intact. Tea was soaking into the elaborate design, where it would become all but invisible ...

He parked on Buccleuch Place. The Slavic Studies department was housed in one of the tenements. He tried the secretary’s office first, asked if Dr Colquhoun was around.

‘I haven’t seen him today.’

When Rebus explained what he wanted, the secretary tried a couple of numbers but didn’t find anyone. Then she suggested he take a look in their library, which was one floor up and kept locked. She handed him a key.