‘Dissection became remarkably fashionable among the nobility of Europe in the eighteenth and nineteenth centuries,’ said Robertson. ‘Some of those self-appointed scientists set up their own dissecting laboratories at home, just as you or I might have a billiards table. They took great pleasure in inviting their friends round for the evening whenever the grave robbers had delivered a fresh corpse. Can you imagine that?’

‘No,’ said Cooper. But then, he couldn’t imagine fitting a billiards table into his flat in Welbeck Street either. Presumably an Edwardian gentleman’s residence had its own billiards room, if not a dissecting laboratory.

‘And de Sade wrote about this?’ he asked, moving back slightly to free himself from the professor’s hand.

‘Yes, in La Marquise de Gange,’ said Robertson. ‘What a subject to be occupying a man’s mind when he’s seventy-three, eh? But then, he obviously wasn’t afraid of death.’

Cooper followed Robertson with his eyes as he moved around the study, passing backwards and forwards in front of the window, his bulk creating flashes of light and dark as he talked.

‘Earlier this week, we visited a place called the Infidels’ Cemetery,’ said Cooper.

‘Oh, really?’

‘You’ve not heard of it?’

‘No.’

Cooper was surprised, given Robertson’s interests. But perhaps the graves were too ancient for him.

‘It’s near Monsal Head,’ said Cooper. ‘Just an old graveyard. But there was an inscription on one of the gravestones that I’ve never seen before. I think it was in Latin. I wonder if you’d know what it means.’

‘Try me,’ said Robertson, almost glowing with pleasure at another chance to show off. ‘A memorial inscription, you say?’

‘Yes. I think it was in Latin: caro data vermibus.’

‘Ah yes, very interesting,’ said Robertson.

‘I thought it would be.’

‘Cadaver.’

‘I’m sorry?’

‘It’s an example of an acronymic derivation. The word “cadaver” was believed to derive from the initial letters of your Latin expression caro data vermibus. Literally, it means “meat given to worms”. A perfectly apt phrase – in the case of burial, at any rate.’

Cooper was starting to feel a bit detached from reality as he listened to the professor. He’d come to think of it as a weakness that he could so easily slip into someone else’s world and share their obsession. Most of the obsessions he came across were the kind he’d rather not have in his head, and it looked as though Robertson’s would count among them. He might have to watch some mindless TV tonight to push it out of his mind.

‘Is this your wife, sir?’ said Cooper, at last finding the photograph he’d been looking for. It was tucked away on a lower shelf of the display cabinet, nestling in the gloom between two willow-pattern plates. The glass of the cabinet was smeared, as if someone had touched it with dirty fingers and not cleaned it since.