I managed to keep my voice quiet, though I may have flushed. `I thought you suspected a maggot all along. I thought that was why Titus brought me in!' We clashed eye to eye. Neither achieved supremacy. The sooner I stopped working with Marcus Rubella, the happier I would be. `Petronius Longus will be reporting on the traitor who betrayed Linus when we have discovered who it is.'

`You told him there was a traitor?'

Not even I as Petro's close friend could pretend that Petro had been aware of it. `It seemed best for me to warn him that he needs to be careful whom he trusts, so I did discuss the subject with him last night before we parted company.'

`I suppose that's why you quarrelled?' The reason was between the two of us. Rubella glared. `He and I have also spoken.' Relief. Petro had faced the issue. Petro had even come clean with his tribune. I wondered whether he had asked for an interview of his own accord, or whether Rubella – who was undeniably sharp in his dour way – had realised there had been an error and had insisted they discuss what had gone wrong. `No thoughts on it?' Rubella tried.

I was not inclined to share them. `I'm standing back. Petronius Longus wants to sort it out internally.' I knew that without having any contact with him.

`I have agreed his approach. He'll review events surrounding the failed attempt to send Balbinus into exile. Then he'll interview the entire team individually.' For a moment I experienced the odd feeling that whatever Petro or I said to Rubella would make its way to the other. It was like conversing through an intermediary to save face. Maybe the damned tribune understood men after all. Maybe he could arbitrate.

`Keep me informed,' he concluded, as if confirming it.

Then the hypocrite wished me luck (hoping I would fall flat on my face of course) and I took myself off to apply my special gifts to the world of stolen luxuries.

Rubella had given me the lists of stolen property. I had a quick glance at the endless details of six-foot-high Etruscan terracotta stands and bowls, ancient Athenian red-figure, gilt and jewellery, porphyry and ivory. Then, to deal with two commissions at once, I started with the piece I knew: Papa's glass jug.

There was one character involved in this saga whom nobody else seemed to be considering. So I pulled my cloak around my shoulders and decided to meet Florius. I had to find him first.

LIV

MY BROTHER-IN-LAW Famia, Maia's treasure, prided himself on being a man with contacts. It was rubbish. Famia's contacts were one-legged jockeys and liniment-sellers who drank too much. He was a vet, working for the Greens. Their pathetic choice of horse doctor may account for the fact that as a chariot team they stink.

Famia was no stranger to flagons of non-vintage grape juice himself. He had a florid face with puffy eyes. Maia fed him well and tried to keep him neat, but it was hard work. He favoured a long tunic the colour of estuary mud, over which went a filthy leather apron and a belt from which hung curious tools, some of which he had devised himself. I had never seen him use a single one of them on a sick animal.

I found him sitting on a barrel at the stables, talking to some visitors. A lame horse waited patiently. It appeared to know it stood no chance of attention this week if it had to depend on Famia. Hung on the wall behind it were an impressive selection of harness rings and roundels, blacksmiths' hammers and pliers, and hippo shoes.

`What ho, Falco! I hear you slipped up with your fancy piece?'

`If that's a course reference to my impending fatherhood -'

`Don't be stupid. I presume Helena will be getting rid of it.'

`That so? I like to be kept up to date, Famia. Thanks for telling me!'

`Well, that's the impression Maia gave me anyway.' Realising he was likely to get thumped, he sniffed and backed off. Famia simply could not believe that a senator's daughter would carry an informer's child. I had long given up any attempt to hack a path through the dark undergrowth of his social prejudice. He wasn't worth trying to talk to sensibly.

The bastard had upset me. No use denying it.

It was too much to hope Famia knew Florius, but since Florius was a gambling man Famia must know someone else who did. Prising the information out of him gave me indigestion for the rest of the day. He enjoyed being difficult.

It took me most of the afternoon. A long stream of undesirable characters whom Famia had suggested I consult finally ended with a snooty ex-charioteer who kept a training stable near the Plain of Mars. His office was full of the silver crowns he had won when he himself raced, but somehow lacked the odour of real money that I associate with retired champions, most of whom are nearly millionaires. Famia had hinted darkly there was some scandal attached to him, though needless to say he then sent me in there without saying what. Maybe the fellow tried to diddle on the slave tax when he bought his drivers, and had been found out. Many a hopeful setting up a new business assumes the fiscal rules don't apply to him. Catching them out works wonders for the Treasury's income from fines.

One reason it was so difficult to trace Florius was that it turned out he supported the Whites. `The Whites?' I was incredulous. No wonder he was elusive. Nobody in Rome supports the Whites. Even the Reds are less unpopular. A man who supported the Whites could well wish to remain invisible.

The ex-charioteer thought he might be seeing Florius later. Naturally he viewed me with suspicion. People never entertain the thought that an informer might be tracing folk for a good reason, such as to bring them news of an unexpected legacy. I was interpreted as trouble. It was quite likely Florius would be warned of my visit and advised to avoid me. Determined to better him, I pretended to go along with it, said I'd call back in an hour, and concealed myself in a wine bar to await developments. At least I got a drink.

The racing snob went out in his cloak almost immediately. I gulped down my tipple and followed him. He met Florius at the Pantheon, obviously a regular rendezous. I stood back, but neither was keeping watch for trouble. Shading my eyes against the glitter of the gold tiles on the domed roof, I observed them without them even once looking in my direction. They had a short chat together, fairly unexciting and perhaps even routine business, then the charioteer strolled off again. Florius sat among the forest of columns in Agrippa's confrontational portico. He appeared to be working out figures on a note tablet. I walked across the open area in front of the temple, then slid up to talk to him.

Florius was a mess. He. was a shapeless lump, too heavy for his own good and unkempt with it. His baggy tunic had spots of dried fish pickle down the front. It was untidily hooked up over his belt, from which hung a fat hide purse so old its creases were black and shiny and stiffened with use. His boots had been handsome kneehighs once, but their complex thongs were mud-splashed and needed grease. His feet were badly misshapen with corns; the thick toenails had been hacked short, apparently with a meat knife. His brown hair looked as if it had been cuts in tufts by several barbers over several days. He wore his equestrian ring, plus a haematite seal and a couple of other heavy gold lumps. This was hardly for personal adornment; his fingernails were ferociously bitten, with ragged cuticles. His hands looked in need of a wash.

This neglected bundle received my greeting without alarm. He put away his notes, which looked like details of form. (I craned for a look, hoping they would be lists of stolen goods nothing so obvious.) He was sharp enough in his obsession; as I had approached the temple I had seen him scribbling away with his stylus so rapidly that in minutes his little squiggly figures filled a whole waxed board. I determined not to ask him about racing. He was clearly one of those mad devotees who would bore you to death.