Slaves padded past us, setting out oil lamps. Under our frugal Emperor, there was never quite enough light. The slaves had mastered the art of implying they had too much work to break off and tell us whether the office we were looking for was down the right- or left-hand corridor, let alone to admit whether the imperial family was in residence or had all gone away to some summer villa . . .

Systems here had stayed the same since Tiberius organised this part of the Palatine. The imperial livery had changed and there was less open fornication; little else altered. Emperors came and went while bureaucracy continued, as rampant as mould. Vespasian and Titus lived in Nero’s repulsively opulent Golden House on the other side of the Forum, while élite secretariats kept their old offices in this historic complex. The bigger the name, the grander the office. Laeta had a suite. Its doorknobs were gilded and a quiet slave constantly mopped the marble floor outside. She was probably there to eavesdrop on pre-admission visitors.

‘This place always reeks of suspicion,’ Petro mumbled, keeping an eye on the mopper. Once she looked up and automatically he smiled at her. Like any healthy Roman male, he kept in practice as a flirt.

I agreed. ‘To say they all plot is like saying slugs eat lettuce.’

Laeta worked late. As a bureaucrat he genuinely believed his vital work required more than an ordinary business day, even from an expert like him. He kept us waiting. That was to make us impressed that he should find time for us. Petronius and I slouched on corridor benches below a high, elegant ceiling and remarked loudly that being so disorganised at his rank was pathetic. We made sure the usher heard. Enlivening the life of underlings is a ploy worth spending time on.

Maia and Helena said we had never grown up. We could be mature—though kicking our heels in boredom brought out the worst in us.

Finally Petronius was called in and I followed. When he saw me on his marble threshold, Laeta looked irritated. He was a middle-aged, middle ranker with an astute gaze. He was bursting to ask what I was doing there; he wondered whether somebody had failed to brief him on a policy issue—or, worse, had he been briefed but had forgotten it? He felt obliged to nod a greeting, but some unease showed.

We shimmied across the doormat—a pleasing integral mosaic—and began our next role-play. It involved extravagant respect from Petronius, while I stared as if flattering a senior official had never occurred to me. Petro declared he was honoured to meet such an important man of whom (he said) he had heard much, all of it impressive. Laeta fended off a blush. Everyone must suck up to him, but he was unsure how to take it from us. Well, I said he was astute.