If I had had any sense, I would have ended the partnership while we were standing in front of the wall. I would have told Petro that although I was grateful for his offer; the best way for us to preserve our friendship would be if I just let him doss at my apartment, I would work with someone else. Even if that meant pairing up with Anacrites.

The omens were bad from the very start. My normal method of advertising my services was to march up to the foot of the Capitol, quickly clean off someone else's poster from the best position on the Tabularium, then scrawl up a few swift strokes of chalk, writing whatever jocular message came into my head. Petronius Longus approached life more seriously. He had written out a text. He had worked up several versions (I could see the evidence in his note tablets) and he intended to inscribe his favourite in meticulous lettering, surrounded by a Greek key border drawn in variously hatched patterns.

`No point making it pretty.'

`Don't be so casual, Falco.''

`The aediles will wash it off again.'

`We need to get it right.'

`No, we need to avoid getting spotted doing it." Chalking graffiti on national monuments may not be a crime in the Twelve Tables, but it can lead to a right thrashing.

`I'll do this.'