The villa owner had clout. A search was conducted, though nobody was found. No one then made a link with the Claudii. Volusius gave a description of the two men, but it was too vague. If he had heard names, he could not remember them. He went into shock, too jittery to be of use as a witness. Some people even doubted his story. There was not a scratch on him. Nobody had seen him with the strangers. His fear might not be caused by trauma, but a pre-existing mental problem that made him imagine things. Enquiries petered out.

‘And did he get the job?’ I asked the slave I was talking to.

‘Out of the question. He was a gibbering wreck. A man in that state could not be allowed to give lessons to respectable boys. He never even met them.’

‘What happened to him?’

‘He went back to Rome.’

‘Was he fit to travel? After such an ordeal, didn’t he panic at the prospect?’

‘We kept him here a few days. He was allowed to write a letter and his mother came for him.’

‘Got her address by any chance?’

‘Afraid not, Falco.’

‘We’ve lost him then . . .’

‘Why do you need to find him? It’s all here.’

‘And it’s invaluable, thank you. But we now believe the two men existed all right and there is an idea who they are. Volusius, as the only known survivor, might be able to identify them.’

‘I bet he’d still panic, even after all these years.’

‘Maybe. We have to hope seeing them in custody will reassure him . . . Tell me, what was the point of offering him a job here? Don’t boys in a wealthy family have their own private tutor? Were they so dumb, they needed extra cramming in the summer holidays?’

‘Excuse me! Quite the opposite. My master’s sons had an all-round education in which they both excelled. This was to give them special lessons, because they were so gifted and mentally demanding.’ It was to keep them occupied, I guessed, to stop them groping the maids and setting the house on fire. ‘Volusius had a sideline—expertise in algebra.’

Now we were getting somewhere. The vigiles do not keep track of the miserable, half-starved souls who teach urchins the alphabet under street corner awnings, not unless there is a very large number of reports of sexual abuse; or, better still, complaints about noise. But in Rome, playing about with numbers carries dark undertones of magic. Like prostitutes, Christians and informers, therefore, mathematicians are classified by the vigiles as social undesirables. Their details are kept on lists.

48