When the festivals were over and the theatre was taken down, Scaurus sold off some of the decorations and made lavish gifts of others. But much of the stuff he kept for himself, to decorate his new house on the Palatine. Marble veneers and columns were turned into terraces and porticos. The walls of coloured glass were transformed into skylights. Enormous crates full of statues and fabulous draperies and paintings were stacked up in the forecourt of the house and gradually taken inside. For his redesigned atrium, Scaurus decided to instal the largest columns from the theatre, made of black Lucullean marble, each eight times as tall as a man. The columns were so heavy, and hauling them so difficult, that a sewage contractor forced Scaurus to post a bond against possible damages to the city drains when the columns were transported across town to the Palatine.

The house of Scaurus excited almost as much comment as his theatre. People who had gawked at the theatre came to gawk at the house. His more conservative (and less affluent) neighbours considered the place an affront to good taste, a monstrosity of waste and excess, a defamation of stern Roman virtue. Those who complained should have remembered the old Trojan axiom: no matter how appalling a situation, it can always get worse – as when word got out that Scaurus was moving and had sold the place to the rabble-rouser Clodius. Clodius, the high-born patrician who disowned his pedigree to become a plebeian; Clodius, the bane of the Best People; Clodius, the Master of the Mob.

Clodius had paid almost fifteen million sesterces for the house and its furnishings. If the rumour was true – that Clodius was dead – then he had had little time to enjoy the place. He would never see the marble terraces bloom with roses in the spring.

I poked my head through the Attalic draperies into the atrium beyond, where the ceiling abruptly shot up to the height of three storeys. "The Lucullean marble columns!" I whispered to Eco, stepping through the curtains and beckoning for him to follow, for here they were, soaring up in jet-black splendour to the ceiling forty feet above.

In the centre of the atrium was a shallow pool decorated with shimmering mosaic tiles of blue-black and silver, picturing the night sky and the constellations. High above the pool a corresponding square was cut into the roof, but instead of being open to the sky, there appeared to be a vast pane of glass across the skylight, through which the stars wavered as if they were underwater. It was a dizzying conceit: the skylight above appeared to be a pool reflecting the stars at our feet.

I took a slow walk around the perimeter of the atrium. Installed in niches in the walls were the wax masks of family ancestors. Publius Clodius Pulcher came from a very ancient, very noble line. One by one, the faces of his predecessors stared impassively back at me. Most had been captured in maturity or old age, but one could see they were in general a handsome lot. Pulcher – the name of the family branch – means beautiful, after all;

Eco tapped my shoulder. Our escort had returned. He gestured with a toss of his chin and we followed him more deeply into the house.

As we walked down hallways I peered into the rooms on either side. Everywhere I saw reminders that we were in a house that had only recently been moved into and was still unsettled. Boxes and crates were stacked mazelike in some rooms, while other rooms were empty. In some places there was scaffolding and the smell of fresh plaster. Even the rooms which appeared finished seemed somehow tentative – furniture was set at odd angles, pictures were hung in odd spaces, statues were placed too close together.

What had I expected to find inside the house? Women weeping, slaves running about in confusion, a sense of panic? Instead the house was quiet, with hardly a person in sight The vastness of the place made the quiet seem all the more acute and uncanny, like a deserted temple. Occasionally a slave crossed our path, deferentially stepping out of our way and keeping his face averted.

When the body dies, a philosopher once told me, all the life within it contracts to a single point before expiring altogether. So it seemed inside the house of Clodius, that all the life had gathered in one place, for suddenly we rounded a corner and entered a room lit by many lamps and full of hushed voices. Nervous-looking men in togas paced fretfully about, conversing in groups, gesturing with their hands, shaking their heads, arguing in whispers. Slaves stood out of the way in corners, quiet but alert, awaiting instructions.

We came to a closed door at the far side of the room. Nearby a hulking brute of a man sat with his chin in his hands, wearing a miserable expression. There was a bloodstained bandage on his head and a tourniquet around one arm. A handsome young man in an elegant tunic hovered over him, berating him and barely pausing to let the brute answer in mumbles. "I still can't understand how you could have deserted him like that. Why were there so few of you with him in the first place? What in Hades were they thinking when they took him to that tavern instead of back to his villa?"

Our escort gently rapped on the door with the side of his foot; someone had taught him good manners. The young man and the wounded man looked up and peered suspiciously at Eco and me.

The wounded man frowned. "Who in Hades -?"

The young man stared at us dully. "It must be that fellow my Aunt Clodia sent for."

The door opened. A pair of feminine eyes peered out. Our escort cleared, his throat. "The one called Gordianus, and his son, Eco."

The slave girl nodded and opened the door. Eco and I stepped inside. Our escort stayed behind as the girl shut the door.

The room had the feeling of a sanctuary. Thick rugs covered the floor and tapestries covered the walls, muffling the quiet crackling of the single brazier that warmed the room and cast long shadows into the corners. Against one wall there was a long table, like an altar, with a few women clustered before it, their backs turned to us. The women were robed in black, their hair let loose to fall over their shoulders. They seemed not to notice our arrival. The slave girl went to one of them and touched her gently on the elbow. Clodia turned and looked at us from across the room.

I had not seen her for almost four years, since the trial of Marcus Caelius. Clodia had retained my services to assist the prosecution; things had not gone as she planned, and her miscalculations had ended badly for her. Since then she had led a much quieter, more private existence, or so one heard, on the rare occasions when her name was mentioned. But I had not forgotten her. One never forgets a woman like Clodia.

She walked slowly towards us, the hem of her black gown trailing behind her. Her perfume reached us a moment before she did, scenting the air with the essence of crocus and spikenard. I had always seen her with her hair pulled back and held in place by pins. Now she wore it down for grieving, giving a lustrous black frame to the striking angles of her cheekbones and the proud line of her nose. She was past forty now, but her skin was still like white rose petals. Her smooth cheeks and forehead seemed to glow by the flickering light of the brazier. Her eyes – those famous, glittering green eyes – were red from weeping, but her voice was steady.

"Gordianus! I thought I glimpsed you in the crowd. This is your son?"

"My elder son, Eco."

She nodded, blinking back tears. "Come, sit with me." She led us to a corner and gestured for us to sit on one couch while she sat on another. She pressed one hand against her forehead and shut her eyes. She seemed on the verge of sobbing, but after a moment she breathed deeply and sat upright, folding her hands in her lap.

The light from the brazier was interrupted by a shadow. One of the others had crossed the room to join us. She sat beside Clodia and reached for her hands.