I had been forced to take a long route. Anacrites' billet lay at the far end of the Forum, so I had to trek home around the Circus Maximus. I chose to trudge across the valley at the apsidal end, which lay closest, aiming to turn towards the river once I made the far side. Going from the Palatine to the Aventine is a real pig. The monumental racetrack completely blocks your way, and I happened to know that climbing in and walking the length between two great empty banks of seats at night was a great jape only for the young and crazy. I was far too old for dodging night-watchmen. Being somewhere I was not supposed to be no longer held a thrill. I had had to do it too many times in the normal course of my business. Negotiating the arches of the Aqua Marcia and Aqua Appia, I was so near the Capena Gate I took the opportunity to call in on Helena's family. I could boast I was pursuing their lost person by both day and night. As I cut away horn main highways on my short detour to the senator's house, which lay close to the aqueducts, I came down one dark side street where I sensed trouble. I had thought I heard somebody scuttle away as I turned around the corner. Then I stumbled over a pair of legs. I jumped back, with the hairs standing up on my neck.

I was going for my knife, but paused. The figure on the ground lay too still. This did not feel like an ambush, but I made sure no accomplice rushed out of the darkness to rob me. Gingerly, I stretched out one leg and moved rags aside with a toe. The man was dead. I could see no signs of foul play. A stinking vagrant, too rank to inspect closely, had succumbed to cold and hunger, curled up in misery against the bay tree outside some householder's forbidding door.

I listened: silence. If I ran into the vigiles, I could report the corpse. Either they would cart it away routinely or the householder would discover the deceased tomorrow and inform the relevant aedile that something unpleasant needed to be cleared from a respectable street. Another pauper, another runaway slave, another inadequate had lost the fight to survive. Fleas would be hopping off him, searching for a new host, so I kept well back.

I eased my tense shoulders, listened once more, then walked on. At the end of the street I turned back. A fellow-traveller, cloaked and hooded, appeared nom the far shadows, leading a donkey. Unwilling to delay longer when I could offer no help, I slipped into my own patch of shadows and moved off again without speaking. The Camillus door porter was a long-headed loon with a tiny brain and a truculent attitude, whose main delight in life was turning away legitimate visitors. He took his time answering my knock, and then claimed nobody was in. This was traditional. He had known me for six years now, knew I was a regular visitor, knew I was married to Helena. I asked this Janus politely if he could give me some idea how many more aeons I had to endure before I gained rights of entrance. The insufferable squit played dumb.

I was just threatening to beat him so he would recognise me next time, when he was rescued by the senator. Decimus Camillus had heard the commotion and came out in his house slippers to let me in himself. This spared me nom having to decide what I would tell Julia

Justa and Claudia Rufina, and more importantly, what at this stage of uncertainty I would not tell them. However, I relayed to the senator everything I had found out. He said, 'That's not much!' I said, 'Thanks for the vote of confidence.' The Camillus family lived in the more run-down of a pair of houses, spacious by my standards but cramped when compared with most senatorial homes. The senator and I walked quickly, like conspirators, through the black and white tiled hall, where the faded dado had at last been given a repaint, this time in a rather hot orange. Unwise, I thought. I said nothing, in case the senator had chosen it. We ended up in his tiny study, overlooked by statue busts and high shelves of book canisters. Richer men keep their scrolls in ornate silverware; Decimus had wood, but it was delicately scented cedar wood and the fittings were smart. Unlike many an aristocrat, I knew he read the scrolls. His children had grown up welcome to take and read anything they chose; Helena still came back on raids when we needed to research, and I too was allowed borrowing rights.

I cleared a space among the untidy documents, finding a stool hidden beneath the mess. 'It's a tricky situation, sir. The Praetorians were seen arresting your son, and my private information is that Anacrites – who is attached to the Guards, of course – is currently holding him. I take it no one has informed you? Well, that's illegal for starters. You have to decide whether you want to go straight to Vespasian, and make indignant protests. As the Emperor's old friend, as a member of the Senate, and just generally as the father of a free Roman citizen, you can demand an immediate audience.'

We were both silent. Decimus gazed at me. He was tall but stooped, his hair thinner and greyer than when I first knew him; both age and family troubles had taken their toll. 'I see you really want me to wait, Marcus.' He often looked as if he disagreed with my methods, but we rarely fought over it.

I had never shown him fake respect. I told him bluntly, 'I'd like to interview Anacrites first. Find out his game. If that fails, then we have the heavy option.' 'You think the man is dangerous.' 'I think I'd like to remove every hair on his body, using the slow singe method, then baste him with honey and leave him tied up by a hornets' nest.' It would be at a time of my choosing, however. 'He makes a bad enemy. Rationally, therefore, it would be best to extract Quintus without making Anacrites feel he has been publicly overruled. '

'Is Quintus being harmed?' His father tried not to be specific. In prison the risks were starvation, disease, buggery by fellow-prisoners, beating by the jailer, nibbling by rats, chafing of chains, fear, and professional torture.

I tried to ignore the thought that I could not find Anacrites tonight because he was in some dank cell, watching as inquisitors applied their painful techniques to Justinus. 'A senator's son? One to whom Vespasian once promised rapid social advancement? What do you think, sir?' 'I won't be happy until I have him home, Marcus.' 'Well, give me half a day. If I haven't got him back by noon, you go and raise havoc on the Palatine yourself' 'If you do get him back, I may raise havoc anyway!' That was how we left it. It was late now, and I could see that the senator was put out, so I did not even stay for a drink with him. I climbed back over the Aventine, this time making my way past my mother's apartment. To my surprise, she still had a light showing, so I went up. It was possible she was entertaining Aristagoras, a ninety year-old neighbour who had set his sights on her. If so, it was time the flirtatious old bastard tottered back to his own roost and let Ma go to bed.

I let myself in. Every Roman mother's boy is allowed to keep a latch-lifter to the place where he was brought up; every Roman mother hopes one day he will come home again.

Even with Ma's sight failing, everywhere was spotless. I moved gently through the door curtain, and straight into the kitchen. The usual frugal lamp was supplemented by a candelabrum Ma brought out for favoured visitors. Someone was sitting at the big table, with his back to me. He wore a subdued oyster-coloured tunic, decorated with grey and purple braid that must have cost more by the yard than most families had for their weekly food bill. Black hair was combed back on to his neck, where it curled in oily spikes as he hunched over a bowl from which rose wafts of Ma's delicious leek broth. There would be none for me, because the cauldron was already washed and upended on a workbench behind my mother. She herself was sitting with her hands folded on the table.