There had never been legions permanently stationed in the capital: they were always needed forward, to guard the frontiers. Thirty years after its conquest by Rome, Britain still kept four active legions-more than any other province. It was out of proportion and stupidly expensive. It showed Rome's fears, after our near-overthrow by Boudicca.

If there were five hundred soldiers in Londinium, that was pushing it, but they ought to be decent quality. The legions took turns to send men back to the capital on detached duty. In a frontier province even the walking wounded and duffers who had annoyed their legate should be capable of guarding the governor and his staff, impressing visitors, flashing swords in the forum, and patrolling the docks. They had to live somewhere. Information from a passerby took me right to the other side of the forum, across the stream that divided the town, and down the Decumanus, the main street. I ended up on some remote thoroughfare, way out by the amphitheater, a tedious hike. There I found a mess. The western hill had been taken over by whatever units were stationed here to guard the governor, and since the governor rarely stopped in the capital long, they lived in chaos. It was worse than a marching camp-no proper defenses and individual groups of barrack blocks all over the show.

I found my man. He was annoyed at being rooted out but agreed to come and play. I took him for a drink. He could pretend to his mates that I needed specialist advice in private. And in private, I might seduce him into revealing more than he should.

He insisted on taking me to a bar the soldiers liked. By the time we arrived I knew his name was Silvanus. I offered wine, but he preferred beer."That Celtic muck is fermenting in your belly, Silvanus!" I joshed. Pretending to be friends with a man I despised was a strain. "You'll end up like some fat pink Celt."