Their corpse was of average age, height, weight and appearance. As far as they knew, there were no missing persons reported with that description. They thought themselves very clever for noticing the dead man had been bearded and was barefoot.

"Someone stole his boots after they topped him," suggested my father (it was the kind of thing he would have done).

The Urbans then stumbled about the garden in the dark, looking for clues. Surprise! They found nothing. The contractors had been gone a couple of weeks now. One thing they had done really well was to sweep clean the site before they left. "That must have surprised you!" I commented to Pa. He laughed grimly. We knew now why they were so careful.

The dumb cohort boys caused themselves a lot of confusion when they discovered the tools Pa and I had been using earlier in his garden. After a bit of arguing, we managed to deflect them from that little byway, then they lost interest. They convinced themselves they knew who had killed the man. I pointed out that while somebody working on the bath house might be responsible, there was no proof. They saw me as a troublemaker, and ignored that. They sauntered off into the night, believing this one was easy.

Two days later a sad officer called on Pa at the Saepta Julia. By now the Urbans were greatly miffed that no solution had been dropped into their laps by the gods. All they knew was that Gloccus and Cotta had both left Rome. While this seemed to confirm their guilt, it meant no arrest. Were we surprised? What do you think?

The Urban Prefect wanted to clear up the case and the situation was even worse for me. Pa expected me to take over when the real I

investigators feebly dropped out.

Well, at least it could be a training exercise for my bright young assistants.

Young, yes; bright, perhaps. Assisting- no chance. I got more help from Nux. The lads were an unlikely pair for informing. Friends of mine thought they would quickly tire of me. I reckoned I would soon be dumping them.

Helena Justina had two well-brought-up patrician brothers: Aulus Camillus Aelianus and Quintus Camillus Justinus. When I first knew her, both had looked promising citizens Justinus, the younger, especially. He and I shared some foreign adventures; I liked him and although he could behave like an idiot, I was impressed by his abilities. I never expected to work much with him because he seemed cut out for higher things.

Aelianus, two years the elder, had been on the verge of standing for the Senate. To look respectable, he became betrothed to an heiress from Baetica, Claudia Rufma. A nice enough girl, with extremely nice financial assets. Then Justinus stupidly eloped with Claudia. They were in love when they ran off, though probably not now.

The abandoned Aelianus felt a fool and refused to go through with the Senate election. He had a point. The family had already survived a political crisis when an uncle tried some dangerous plotting. Now public scandal gathered again. All the chalk-white robes in Rome could not really make Aelianus look a pristine candidate, one with illustrious ancestors and blameless modern relatives.

Deprived of his expectations and in retaliation, while Justinus was away marrying the heiress in Spain, Aelianus wormed his way in with me. He knew Justinus was planning to come home to work with me, and hoped to steal the position. (What position? sceptics might well ask.)

Justinus reappeared in Rome early that spring, not long after my daughter Sosia Favonia was born. Claudia had married him. We had all thought she might lose interest (mainly because Justinus already had), but they were both too stubborn to admit their mistake. Her rich grandparents had bestowed some money on the pair, though Justinus told me privately it was not enough. He appealed to me for support, and since he had always been my favourite, I was stuck.

I did escape one hairy proposal: Helena had talked about Justinus and Claudia coming to live with us. But their first visit on their return to Rome coincided with one of our nursemaid's days off. While Hyspale was gallivanting on yet another shopping trip, Julia was racing about our new home's corridors with Nux. My dog thought being 'good with children' meant pretending to savage them, so that was noisy. Nux smelt too. Mico's Valentinianus must have rubbed bits of gherkin into her fur. At the same time, the baby who picked up tricks very quickly- had just learned how to turn herself blue with hysteria. Dear Favonia was well tended, but an unkind father might say babies produce as many smells as dogs. So our newly-weds backed out of sharing accommodation rapidly. I'm sure I would have begged them to reconsider, if I had thought of it.

Over the job, however, Justinus refused to give way to his brother. So now I had both lads at my tunic tails. It was a misery to their parents, who had already lost their daughter to the low-life Didius Falco; now both their noble boys were coming to play in the gutter as well. Meanwhile, I had to keep the jealous pair apart.

I gave them the bath house incident to experiment with. They had been hoping for more impressive clients than Pa. For instance, ones who would pay fees.

"Wrong," I explained harshly. "This man is excellent to start with. Why? Now you learn about clients. As informers, you must always out manoeuvre the devious crook who commissions you: weigh him up first!

My father, whom you know as Didius Geminus, is really called Didius Favonius -so right from scratch, you're tracing a fake name. With a client, this is typical. He has led a double life; he runs a shady business; you can't believe a word he says; and he'll try to duck out of paying you."

My two runners gazed at me. They were in their mid-twenties. Both had dark hair, which like aristocrats they left to flop annoyingly. Once a few derisive barmaids had pulled it, they would learn. Aelianus was thicker set, a little more untidy, a lot more truculent. Justinus, finer featured and better mannered, had more of a look of Helena. They were entitled to wear white tunics with purple bands to show their rank, but they came to work, as I had instructed, in subdued clothes and nothing fancier than signet rings. They still sounded so well-spoken I winced, yet Justinus at least had an ear for languages, so we could work on that. Unobtrusive behaviour would help. If ever they got in deep trouble, they had both been through army training; even as junior st aft officers, they knew how to put in the boot. I was now sending them to Glaucus, the trainer at my gym; I had told him to slaughter them.

"So," Aelianus condescended to address his younger brother. "We have learned today that our mentor, Marcus Didius, holds his papa in traditional respect!"

"It sounds," Justinus said to me, grinning, 'as if we should look at your father as the most likely killer."

Even I had never thought of that. But with Pa, yes: it was a possibility.