They had melded in, apparently very fast and without effort. Londinium had accepted extortion as easily as it accepted mist every morning and rain four times a week. That was how the rackets worked. The enforcers arrived in a place and made out that their methods were a normal part of the high life. People could sniff money when near them. Moneyed bastards will always attract sad people who yearn for better things. These thugs-they were no better-soon acquired status. Once they had beaten up a few stubborn customers, they carried another smell too: danger. That also has a perverse attraction.

I saw it all working when they led me right back where I came from earlier, straight past the Swan to the other caupona, the Ganymede. They were well known to the waiter, who came out at once and chatted as he laid their table, a private one set slightly apart from the rest. It was lunchtime and a lot of people were calling for a hasty bite, but the enforcers were able to take all the time they liked over whether they wanted olives in brine or in aromatic oil. Wine came automatically, probably in their special cups.

Pyro went inside, perhaps to visit the latrine, more likely to stash the money from their morning round. I had obviously found their operating base. Here, Splice and Pyro were openly holding court. Male visitors came and went constantly, like cousins at a Greek barber's. On arrival there would be formal standing up and handshakes. The two enforcers then got on with lunch, rarely offering hospitality, rarely being bought drinks. The point for everyone was to make contact. They were businesslike and even abstemious; they ate stuffed pancakes with simple side salads, no sweetmeats, and their wine flagon was the small size. The visitors would sit and gossip for a respectable period, then leave after more handshakes.

I saw no sign that Splice and Pyro were being brought bribes or payments. People just wanted to register respect. Just as in Rome a great man holding public office will receive clients, supplicants, and friends in the formal rooms of his pillared house at set hours every morning, so these two lice allowed fawners to assemble at their table on a daily basis. Nobody handed out presents, though it was evident that this was a favor exchange. On one side, reverence was being offered in a way that made me bilious; on the other, the enforcers promised not to break the supplicants' bones.

Passersby who did not choose to stop and grovel used the far side of the road. There were not many.

I had positioned myself outside a booth selling locks. Unfortunately, as I pretended to peruse the intricate metalwork, I was standing in full sun. Only I could land myself a job in a province famous for its chilly fog on the one week in a decade when the heat would make a sand lizard faint. My tunic had glued itself to my body right across my shoulders and all down my back. My hair felt like a heavy fur rug. The inner soles of my boots were wet and slippery; a boot-thong that had never given trouble before had now blistered my heel raw.

While I stood there, I was pondering a complication: Petronius. Had I been working alone, I would have returned to the procurator's residence to request a posse to arrest Splice and Pyro and search their base. I would then have the thugs incommunicado for so long that some of their victims might be reassured enough to speak out. The governor's inquiry team, his rough quaestiones, could meanwhile have played with the enforcers, using their nastiest instruments of coercion. The interrogators, who must be bored out here, were trained to persist. If Splice and Pyro felt enough pain and found their isolation too terrible, they might even scream out the name of the man who was paying them.

It seemed a good solution. But I could still hear those terse words from Petronius: leave it, or I'm a dead man.

Whatever he was doing, we had been wrong to suspect flirtation or debauchery. He was working, the devious hypocrite. He was under cover somehow. On what? The Verovolcus case had clearly intrigued him, though I failed to see the draw myself; I was puzzled by it, but I was only pursuing out of loyalty to Hilaris, Frontinus, and the old King. Petronius Longus had no such ties. I had no idea why Petro should get involved. But if he was watching these two bullies, I would not move against them before consulting them. That was a rule of our friendship.

I was still fretting over this when a passerby who did not know the local respect system came tripping along: my sister Maia. What was she doing? Unaware of the two enforcers, she walked straight past the Ganymede on their side of the street. That meant I had no chance to warn her off, or ask why she was here. Wanting to stay unobtrusive, I could only watch.

Maia was striking to look at, but she had grown up in Rome. She knew how to pass safely through streets full of obnoxious types. Her walk was quietly purposeful, and although she looked briefly into every shop and food place, she never met anyone's eye. With her head and body wrapped in a long veil, she had disguised her private style and became unremarkable. One man did lean over a rail and say something to her as she passed-some mutt who on principle had a try at anything in a stola-but as my fists balled, that chancer was treated to such a savage look he shrank back. He certainly knew he had encountered proud Roman womanhood.

Mind you, my sister's self-possessed disdain could itself attract attention. One of the men with Splice and Pyro stood up. At once Pyro spoke to him and he sat down again. Maia had by then gone past the Ganymede.

Nice thought: that the enforcers had a noble regard for women! But they just left women alone to avoid attracting the wrong public notice. Gangs who work through fear understand, if they are efficient, that normal life should be allowed to flow through the streets unhindered. Some even go so far as to batter a known rapist or threaten an adolescent burglar, as a sign that they represent order, men who will protect their own. This implies they are the only force of order. Then the people they are threatening feel they have nowhere to turn for help.

They had finished their lunch. They stood up and left. As far as I saw, there was no attempt to offer them a bill. Neither of them left money anyway.

I followed them around for the early part of the afternoon. From place to place they went like election candidates, often not even speaking to people, just making their presence felt. They did not appear to be collecting. That would be better done after dusk. More worrying, and the wine bars would have more cash in the float.

Soon they returned to the Ganymede and this time went indoors, no doubt for a good Roman siesta. I gave up. I was ready for home. My feet were taking special care to remind me how many hours I had been out walking. When I saw a small bathhouse, the feet headed that way on their own. I stopped them when I spotted Petronius Longus already on the porch.

I was desperate to talk to him. I wanted to discuss the gangsters, and I had to tell him of his children's deaths. But I took his warning to heart.

So far he had not noticed me. I stood still, in what passed for a colonnade-hardly what Rome would know as a grand arcade. Petro made no move to enter the baths, but stood talking to a ticket man who had come out for air. They seemed to know each other. They looked up at the sky as if discussing whether the heat wave would persist. When new customers drew the gateman indoors, Petronius settled down on a small bench outside as if he were a fixture at the baths.

This street had a slight curve and was so narrow that by crossing over to the other pavement I could walk up close, keeping tight against the wall, without Petro seeing me. His back was slightly turned in any case. A neat bank of cut furnace logs, nearly four feet high, was stacked- blocking the pavement of course-on the bathhouse boundary. This made the road almost impassable but formed a tiny free area outside the premises next door. The baths were unnamed, but the neighboring hovel had a painted sign with red Roman lettering, calling itself the Old Neighbour. I passed the open door and saw a dark interior whose purpose was undetectable. It looked more like a private house than a commercial property, despite the sign.