Then, just as Aulus was forcing a beaker of water down the Librarian - with a grip that showed our boy really had been in the army - two pathetic little barefoot figures appeared in the doorway: Julia and Favonia were bawling their eyes out, having woken in a strange house all alone.

Uncle Fulvius growled. Helena and Albia jumped up and rushed from the room, carrying the children back to bed. Albia must have stayed with them. By the time Helena returned to the dining room, the third course had been brought and the slaves had withdrawn. We men had redoubled the pace of our wine intake and were talking about horse-racing.

V

Horseflesh, surprisingly, was the Librarian’s best topic. Aulus and I could hold our own, while Fulvius and Cassius spoke of legendary contests run by noble beasts in international hippodromes, using colourful and sometimes off-colour anecdotes.

Helena commandeered the wine flagon, to forget us being sports bores. Roman men magnanimously take their women to dinner parties, but that doesn’t mean we bother talking to them. But Helena would not tolerate staying in the women’s quarters like a good Greek wife, letting her man go out to be entertained by a professional party girl. She had had a husband once, before me, who tried to go solo: she served him with a divorce notice.

We were a team: she refrained from nagging me, and when the party broke up, I made sure I found her buried among a pile of cushions and hauled her to bed. I can undress a woman who says she is too sleepy. Anyone can see where sleeve-buttons are. Helena was sober enough to flop around in the right directions. She just liked the attention; it was good fun for me too.

I spread her red dress neatly on a chest, placing ear-rings and so forth upon it. I threw my tunic on a stool. I crawled into bed beside Helena, thinking how good it would be to have a lie-in next day, before another of my uncle’s leisurely all-morning breakfasts on his gently sunlit roof terrace. Afterwards, perhaps, now that I had met him, I might go and annoy Theon by poking around his Library and asking him to show me how the catalogue system worked . . .

No luck. First, our daughters found out where our room was. Still feeling neglected, they made sure we knew it. We were woken by two hard artillery rocks plummeting at our prone bodies then squirming between us. Somehow we had produced children with iron heads and fast-kicking powerful rabbits’ feet.

‘Why do you not have a nursemaid to look after them?’ Uncle Fulvius had asked, in genuine bafflement. I had explained that the last slave I bought for that purpose found Julia and Favonia such hard work she announced she would be our cook instead. It added to his incomprehension. Fulvius should have known all about family chaos; he grew up on the same crazy farm as my mother. His brain seemed to have blanked out the misery. Perhaps mine would one day.

The next horror was a disturbed breakfast.

Barely had we slumped under the pergola, than we heard footsteps thumping loudly up the stairs. I could tell they meant trouble. Fulvius also seemed to recognise military boots. Given that his house rules were firm about not attracting this kind of attention, it was remarkable how fast he reacted. He struggled to get up, intending to take the newcomers downstairs somewhere private, but after his night of revelry was just too sluggish. Three men stomped out on to the terrace.

‘Ooh - soldiers!’ Helena murmured. ‘What have you been up to, Fulvius?’

As far as I remembered from desultory checks before we left Rome, there were two legions in Egypt, though supposedly they exercised control with a light hand. Having the Prefect in Alexandria meant troops had to be permanently stationed here to show he meant business. Currently, those who were not up-country occupied a double fort at Nicopolis, the new Roman suburb on the eastern side that Augustus had built. Geographically, this fort was in the wrong place - right in the north of a long, narrow province while the brigands were a long way south, preying on the Red Sea ports, and any over-border incursions from Ethiopia and Nubia were even further away. Worse, during the Nile floods, Nicopolis was inaccessible except by punt. Still, the Alexandrian mob had a rowdy reputation. It was useful to have troops close by to cover that, and the Prefect could feel big, going around with armed escorts.

Apparently the militia also carried out certain law enforcement duties that in Rome would fall to the vigiles. So instead of the equivalent of my friend Petronius Longus, we had a visitation from a centurion and two sidekicks. Before they even said what they wanted, my uncle assumed the look of a naughty stable-boy. He rushed to lead away the centurion to his study - though the soldiers pretended they thought it was more discreet for them to stay behind on the roof terrace to supervise the rest of us. They had spotted the food, of course.

Good ploy, noble squaddies! I immediately questioned them on what had brought them to annoy my uncle.

They were commendably demure - for all of five minutes. Helena Justina soon softened them up. She filled fresh bread rolls with sliced sausage for them, while Albia passed around olive bowls. No soldier has been born who can resist a very polite seventeen-year-old girl with clean hair and dainty bead necklaces; she must have reminded them of their little sisters back at home.

‘So what’s the big mystery?’ I asked them, grinning.

Their names were Mammius and Cotius, a long streak of wind with a broken belt-buckle and a short pot of pig’s fat with his neck-scarf missing. They wriggled with embarrassment, but through mouthfuls of breakfast they inevitably told me.

Theon, the Librarian, had been found in his office that morning. A garland of roses, myrtle and green leaves, the garland with which Cassius had bedecked all of us last night at dinner, was lying on his work-table. This garland was a special order, about which Cassius had been meticulous, personally selecting the choice of leaves and style. It had led their centurion to the flower-seller who made it - and she fingered Cassius from the address where she delivered the foliage. Egypt was a bureaucratic province so the house was on some register as rented by Uncle Fulvius.

‘What was up with Theon?’

‘Dead.’

‘Dead! But he never ate any of the pastry chef’s poisoned cakes!’ Helena laughed to Albia. The soldiers became nervous and pretended they had not heard her.

‘Foul play?’ I asked, making it casual.

‘No comment,’ announced Mammius with great formality.

‘Does that mean you were not told, or you never saw the body?’

‘Never saw it,’ swore Cotius self-righteously.

‘Well, nice lads don’t want to go looking at corpses. It might make you queasy ... So why was the army called in? Is that usual?’

Because, the lads informed us (lowering their voices), Theon’s office was locked. People had had to break the door down. There was no key, not in his door, on his person, or anywhere inside the room. The Great Library was stuffed with mathematicians and other scholars, who were drawn to the commotion nosily; these great minds deduced that someone else had locked Theon in. In the traditions of the academic world, they loudly announced their discovery. A rumour flew around that the circumstances were suspicious.

The mathematicians had wanted to solve the puzzle of this locked room themselves, but a jealous philosophy student who believed in civic order, reported it to the Prefect’s office.

‘The snitching beggar must have scampered there on very fast little legs!’As soldiers, my informants were fascinated to think anyone would ever involve the authorities voluntarily.

‘Perhaps the student wants to work in administration when he gets a real job. He thinks this will enhance his profile,’ Helena sniggered.