I walked back out onto the porch again, giving Petro the chance to stroll quietly after me.

"What's going on?" he murmured.

"Helena's protegee." We stood side by side, looking at the street, and spoke matter-of-factly as if we were strangers exchanging polite words while one of us waited for a friend. "I have something to tell you, Lucius." I had to pretend not to know about Maia. "It's about your family-"

"Skip it. I know."

"Ah… We're heartbroken for you. They were lovely girls."

Petronius said nothing. I could feel him enforcing tight self-control. In the end he muttered, "So what brings you here?"

I could play it that way. I wanted his advice. "I think I've just barged into a child prostitute racket."

"You stole that girl out of the brothel, Falco? That could be foolish."

"Helena is sheltering that sad scrap. She was mine in the first place."

"Tell them that! Did they see you?"

"Afraid so. They call it the Old Neighbour. I just met the old neighbor's mummified grandmother."

"She'll make a vicious enemy," Petronius warned.

"I can handle it. You've noticed her?" His reply was a grunt. "Who's the Collector?" I asked.

Petronius gave me a sharp look. "Pimp who collects new bait." He paused. "Dangerous." After a moment, he told me the full rubric. "You know how it works. They prey on vulnerable girls. The Collector's on the streets picking them up. Takes them in, rapes and batters them, makes them believe they are worthless, pretends they have no opinion, fits them up in some drab hole and then works them to death. Only management profit. The punters are charged, overcharged, and robbed. The old bag keeps the new flesh in her filthy claws until it's submissive, then the pimp runs the girls until they drop."

I exclaimed angrily. I tried convincing myself Albia had not been part of this trade previously. When they kidnapped her she knew what was coming, but she took her chance to appeal for help and I got to her just in time.

"So," I demanded slowly. "Longus, my old mucker, are you on observation over the vice game?"

"I am on obbo," he agreed tersely.

"Vice?"

"Vice. And everything else."

"Do I dare ask how come?"

"No, Falco."

"Did you join the Ostia cohort?"

"Doesn't work that way. The Ostia vigiles are not a separate cohort. Ostia is covered by outstationed members of the Rome regulars; the cohorts provide them on rotation. I'm still with the Fourth."

"So is it Rome or Ostia that has taken an interest in Britain?" I asked dryly.

"Both, Falco."

"And the governor does not know?"

"I believe not." Petro's note of uncertainty was rhetoric. He knew all right.

"You are not supposed to be here. What are the vigiles up to, stretching their arms overseas? And secretly?" It must be a secret. If the Prefect of Vigiles asked permission to send men here, the answer would be negative. The army dealt with everything in the provinces. The governor held sole authority; Frontinus would be outraged by this sly maneuver. Even supposing Petro's superiors had sent him-and I assumed they had, since they knew where to write him-if he were caught here working they would disclaim any knowledge of the mission. Arrest would be the least of his problems with Frontinus. "I'll ask again, you reprobate: how come?"

Petronius was standing with his arms folded. I could sense a new dark mood in him, yet he was still himself. Big, generally placid, shrewd, capable, dependable. A pity about his rebuff to my sister, in fact. A shame about her previous rebuffs to him.

"You're playing the muscle at this bathhouse?" I guessed. "But that's a cover?"

"I'm looking for someone," he admitted. "Maybe two men. We know one came out to Britain for sure, and the other's gone missing from Rome. There are henchman involved too, but the operation is to catch the big pair."

"You're talking about a major gang?"

"Yes, real bastards. They caught attention in Ostia, though Rome is their base. We think they have targeted Britain as a new regional market. They have put managers in place, a whole development team, and it looks as if the leaders are currently over here setting things up. So I'm here too."

"You and how many?"

"Me," he said. "Just me." I shivered; maybe he did too.

"Pigshit, Petro." At that point I did turn to look at him. "This is a doomed errand." Petronius Longus, a man of quiet intelligence, did not disagree. "I am with you if you want," I then commented. He could respond, or dump my offer.

"Your presence in this godforsaken province," Petronius confirmed ruefully, "was the sole benefit when I took the job."

"Thanks for that." I stared back at the street again. "I suppose I must not say you could have bloody well told me."

"That's right," returned Petro. "Don't say it."

Who knows what he was thinking, the rogue? At least he seemed pleased that we were now talking. I was pleased myself. "Why you, though?" I asked.

"I know Britain. And it's personal." I was surprised. Petronius Longus was more self-collected normally. "I want to get one of the principals." His voice was dark. "I've been watching him for a long time."

"And there's another out here?"

"New partner. A man we have never identified. We know he exists, but he has kept his face hidden. I'm hoping to put a name to him while I'm here. He should be visible-a Roman setting up an elaborate crime network of a type that never existed in Britain before."

"And what about the one you want?"

"He could be anywhere-but I believe he's here with his partner."

"And who is he?"

Petronius thought of telling me, then for some reason kept his own counsel. My work had rarely ventured into the gangland world; presumably the name would mean little. "So long as it's not bloody Florius this time."

"What a joker you are, Falco!" Petronius clapped my shoulder and then smiled sadly. Florius had been the useless husband of his ill-chosen young lover, Milvia. Milvia came from the worst background. Her dead father had been a major racketeer; her mother still was. If anything, she Was more criminal than the father. Florius, her pathetic husband, didn't count. For Petro, little Milvia was in the past-and we let the subject drop.

"Are you living here?" I asked, jerking my head at the baths. "No. Across the river. There's a mansio." An official travel lodge. "It's not bad. I can see who comes and goes into town."

"How do I find it?"

"Don't show yourself there, Falco."

"No, I won't-but tell me how to find it anyway." We were almost joshing in the old way.

"Go over by ferry and it's obvious."

"I'll remember not to do that."

"Good. I won't see you then!"

Albia came out. Her idea of cleaning up was feeble, but she had replaced her dress, which covered much of the grime. The brothel odors seemed to cling. There was nothing more I could do about that.

Petronius returned indoors. I led Albia back up the narrow street, ducking into the colonnade to be less noticeable. A mistake. Suddenly the witch from the Old Neighbour leaped out at us from a doorway. She had her talons into Albia before I could react.

The girl squealed. It was a scared noise, but filled with resignation. She had been a victim all her short life. Rescue had seemed too good to last.

Disgust thickened my throat again. As the old woman madly tried to drag the girl back to her stinking house, I grabbed some brooms from a besom stall. I don't normally attack grannies, but this hag was outrageous and I know when to break rules. I beat at the short, overweight figure, thrashing her furiously while I yelled for Albia to escape.

No good. She was too used to cringing, too used to taking punishment. The cathouse-keeper was hauling her along, partly by one arm, partly by her hair. At the same time, the old woman had managed to disarm me of my brooms. As they scrabbled on the pavement outside a vegetable shop, I began to pelt the kidnapper with anything I could grab: cabbages, carrots, neatly tied bundles of hard asparagus. Albia may have been struck by a flying brassica by accident; she was screaming much louder now.