‘Mother is happy, so I’m happy—and you will be happy too. You don’t want us littering up your smart hall every morning.’

‘Is that going to happen?’

‘Yes, Marcus darling—’ Marcia did a priceless imitation of her effusive mama. ‘Until you give in, I shall be dumped here to work on you.’

I said I was packing for a business trip to Latium.

My niece turned withering great brown eyes on me. What she lacked in her mother’s extraordinary beauty—and she was on course to inherit most of that—she made up in character. If the character was dubious, it only proved a Didius really had spawned her. A handful at three, at ten she was now ferociously bright and spirited.

Marcia suggested that, if I was busy, I should simply give her the password for my Forum bankbox, then she would withdraw a sum she thought suitable. Nothokleptes, my banker, would probably be so surprised he would hand over everything.

I said Marcia must be joking, then we both collapsed in giggles.

Two days later it was Marcia, a dedicated gossip-winkler, who told me that Petro’s brother was at Maia’s house.

‘Petronius must have sent for him. Auntie Maia is put out.’

‘Nobody knew Lucius even had a brother!’ Helena exclaimed. We were at lunch, tucking into our own goat’s cheese, olives and flatbread, plus more sardines; Marina’s scaffolder must be really keen on her, though he had a tedious diet.

‘Lucius has a brother.’ I wiped my oily chin on a napkin. ‘Rectus. He lives in the country; Petro despises that.’

‘His brother is always off-colour,’ Marcia informed us. Information stuck to her like mud on a wall. ‘He has marsh fever. First it nearly killed him, now it keeps coming back. But Lucius Petronius has turned down the official guide you were offered by the man at the Palace and asked his brother instead. He trusts him. Anyway, he’s brought Nero.’

‘Spot!’ Helena and I corrected her briskly. Nero was an ox, of dubiously rakish character. Petronius, his poorly brother and some hick cousins jointly owned him. Calling the beast by the name of an emperor who had been damned-to-the-memory could be defined as an offence. I was once arrested for it in Herculaneum—though the real reason was that Spot tried to rape a donkey. A snooty Herculaneum citizen, its owner, failed to see the funny side.

‘If this is the same ox, he’s a sex maniac. I’m not driving him!’

‘Why do you need a guide?’ Helena interrupted, swift to pick up any detail I was trying to hide. She homed in on the fact that when I first discussed Laeta’s mission, I implied Petro and I were just retracing my journey to Antium. She fixed me with accusing eyes. I acted casual. It never works.