It was important that nobody noticed me looking. That ruled out knocking on the door at Anacrites’ house, pretending to sell hot sausages; his staff knew who I was. Even worse would have been showing my face on the Palatine, asking the clerk in the office, Phileros, for details of his whereabouts, allowing the rheumy-eyed Momus to spot me, contacting that snake Laeta. They might all guess my role later; I could live with suspicion. But I must leave no trace of the process. There was no point conducting this kind of operation if it left new witnesses who could apply new pressure. We wanted clean air and a quiet life, with no further harassment.

I spent much of the day checking known haunts. That was depressing. Anacrites had pitiful taste in lunch bars. I watched Ma’s house for an hour or so, but she was entertaining Aristagoras, her ninety-year-old smooch. Anacrites must be in his office, working his ordinary day. Arrive, work, plot, gloat, leave for bath and dinner.

At the eighth hour I made my way somewhere I had never been before, though I had heard of it, back in the days when Anacrites and I worked together on the Census. He had told me then it was his favourite and I had stored the information in an empty brain cell, for potential use one day. It was an expensive private bath house on the south end of the Circus, in a short sunny street near the Temple of Sol and Luna.

Nobody knew me. The cloakroom boy confirmed Anacrites was there. I said I was an off-duty investment consultant and the spy had agreed to see me about buying a dog-collar factory in Bithynia. Madness always pays off. They let me in straight away.

My quarry was at that moment not plying his strigil in a steam room; he had moved on and was secluded in a curtained room, experiencing—though certainly not enjoying—the attentions of a team of personal hygienists. I could have waited for him to emerge, but not waiting was so much more fun.

They had a security system, designed to put off the inquisitive: they simply told anyone to push off, if they insensitively noticed screaming. The bouncer was a plump dwarf in a short tight white tunic, who doubled as manicurist. She offered me a half-price cuticle tidy up, but I declined without regret.

‘No time, precious. I am absolutely bursting to see my dear old friend in here—don’t worry, he always lets me come and watch. We have no secrets!’

Well, until today he had had this one.

I whipped aside a sagging length of moth-eaten purple cloth that gave clients imagined privacy. I would not have put myself in this position without an oak door, five-tumbler barrel locks, armed guards and an attack dog.