‘I hope we can tie it to Modestus’ wife, Livia Primilla. From the nephew’s vagueness when I asked about any distinguishing jewellery she wore, I don’t think he would recognise it, but he said she wore good stuff.’

Petronius perked up. ‘If it was her, and if she was wearing this when she disappeared, there is a chance we can identify it.’

He told us that the Fifth Cohort had picked up a runaway slave living rough near the Porta Metrovia, who was called Syrus. They were bringing him over to the Fourth that night, for quizzing about whether he was the Syrus given to the butcher by Sextus Silanus—the one who had waved Primilla off when she went to see the Claudii.

‘Couldn’t the Fifth have asked him for themselves?’

‘They could have tried,’ said Petro. ‘But the slave’s scared to talk and everyone knows Sergius is the best in the business.’

Sergius was the Fourth Cohort’s torturer.

At this point I would have left Albia at Maia’s house; sensing a brush-off, she insisted on coming to the station house with us.

Sergius was waiting for Petronius to arrive before he started. He had stashed Syrus in a small cell, like someone marinating a choice cut of meat for a few hours before grilling.

‘You could just ask the man,’ Albia suggested. It could have been Helena talking.

‘Not half the fun,’ said Sergius. ‘Besides, the slave’s evidence will only count if he screams it out while I’m thrashing him. The theory is, pain will make him honest.’

‘Does it work in practice, Sergius?’

‘Once in a while.’

‘How can you tell whether what he says is true or not?’

‘You can’t. But then you can’t tell when you’re questioning a free citizen either. Most of them lie. That applies whether they have something real to hide—or are just being buggers on principle.’

I thought Albia might have been upset by the whip man’s attitude, but young girls are tough. She listened quietly, filing away the details in that strange little head of hers. ‘If this is the right slave, what will happen to him?’

‘He will be whipped hard, for causing us trouble, then returned to whoever owns him.’

‘No choice?’

‘Certainly not. He is their property.’

‘A non-person?’

‘That’s the definition.’

Albia accepted this as one more fact that showed Romans were cruel—assuming that idea was what caused her enquiry. Sometimes she was unreadable.

Albia turned her pale little face to me. ‘Do you think coming from a rough, hard background, being treated badly in their slave generation, explains why those Claudii turned out as they are?’