‘Yep,’ said Scholz. ‘But I wasn’t as sure of it as you were. I thought the weight of the flesh was perhaps the significant thing. A pound of flesh.’ Scholz said it in heavily accented English. He paused and contemplated his beer. ‘Do you think there’s any chance that our guy is motivated by something other than sexual cannibalism? Given that there’s no semen found at the scenes.’

‘Lack of semen doesn’t mean he didn’t ejaculate. Just that he’s been careful not to leave forensic traces. Or maybe he masturbates later, away from the scene. But let’s say we’re not dealing with a case of sexual cannibalism. Maybe he just likes the taste. The experience of eating human flesh.’

‘What’s to like?’

‘Well, there is one theory that because of the complex proteins in human flesh some people actually get a high out of eating it. A sort of euphoria. Others believe that they gain life-giving complexes that can’t be obtained from other meat sources. But there’s a natural imperative against cannibalism. In both humans and animals it tends to cause prion diseases … mad-cow disease, kuru, that sort of thing.’

‘Could it just be that the killer is simply experimenting? That he just wanted to find out what it was like to eat human flesh?’

‘I like a nice steak now and again,’ said Fabel. ‘But I don’t think I could go into a field and slaughter a cow to get one. We tend to keep the source of what we eat at a moral arm’s length. An American journalist bribed a mortuary attendant in Paris to get a piece of fresh human flesh and wrote about the experience of cooking and eating it. Tasted like veal, he said. Anyway, it’s a hell of a leap to kill – and kill twice – just to satisfy your epicurean curiosity. I would put my money on him fulfilling some kind of sexual fantasy with these murders.’

Scholz gathered up the pizza boxes. While Scholz was in the kitchen, Fabel took in the Cologne detective’s apartment. It had all the hallmarks of a bachelor’s apartment: a combination of the practical and the slovenly. There was a range of house plants dotted around in various stages of dehydration and death: Fabel had to resist the temptation to ask for a watering can. The bookshelves, however, were packed but orderly and Scholz had a spectacularly wide range of DVDs, arranged in alphabetical order by title. This meticulous organisation shouted out from the chaos of Scholz’s flat. There were a handful of surprisingly tasteful art prints on the walls and a poster for a Cologne production of Macbeth. Fabel recalled the Shakespearean reference in his report. Scholz came back with two more beers and cleared room for the files on the coffee table.

‘You like Shakespeare?’ Fabel asked.