'Anything else we should know?' demanded Petronius, becoming more intrigued.

'Anything sexual?' Scythax knew the vigiles' preoccupations in murder. 'Nothing that seems connected. Many vagrants have been abused at some time prior to death, it goes without saying. In those who are clearly runaway slaves, indications of long-term brutalisation are practically generic.' 'Are the corpses all men?' I asked. 'Occasional women. And, sadly, a few children.' I looked at Petro. 'Isn't this wide spread of victims unusual from repeat killers?' He nodded. 'Yes, mostly they go for one consistent type – male or female, adults or children.'

Scythax volunteered, 'I believe the common factor is that the victims live on the streets. They seem to be chosen for punishment because of their indigent lifestyle. Someone finds them sleeping under arches or in doorways, and ends their existence. He – or she – may justify murder as a kindness to end their misery.' 'Putting them down like worn-out horses?' Petronius was shocked and angry.

'Unless,' said Scythax, with his odd dispassionate attitude, 'this killer hates them – sees them as a kind of human vermin. Eradicates them for the greater good.'

'Even more delightful. How will I find this self-appointed Fury?'

'Look for someone who is convinced cleaning up the streets is a decent motive. Of course,' said the doctor diffidently, 'you need to know where to start looking.'

'Io,' replied Petronius glumly. 'Happy Saturnalia!'

The fifth day of the festival brought a turn of the winch.

It started well: we were at breakfast when a message came for me from Petronius. He had obviously buckled down last night to reviewing reports. Among a pile from other cohorts he picked out that the Third had discovered a runaway slave, a teenaged musician. Petro sent a runner over to the Third, who rapidly returned confirmation that they had banged up the Quadrumatus flautist. He did not confess, but when he was rounded up he was carrying a flute. The Third were not bright, but they could add I and I to make III. (According to Petro, III was the only number they knew.) They had chucked the flute away; their tribune hated music in the cells.

I was in my cloak and about to set off for the Third's patrol house to interview the recaptured slave, when a huge litter with gold knobs on the poles turned up on the windy embankment outside my house. The gold was wearing thin and the eight bearers were a lop-sided, shabby set who could not march in time. The conveyance was government issue: some tatty leftover from the imperial transport pool, downgraded from when Claudius or Nero were dragged around in it. Twenty years later it was due for a bonfire. Equally senile, the bearers lurched and dropped it heavily. Out staggered Claudius Laeta and under compulsion I greeted him. He was fetching me to a meeting. Laeta said it was urgent. I knew that meant two things: it wasn't urgent – and the pointless blather would drag on for hours. This was my day ruined.

'I'll fetch my toga.' Helena caught me in the unusual activity, so I lured her into the expedition. That was not hard. After our late night with Maia and Petro, the children were over-tired and squabbling fretfully. Both Helena and I could have coped with the children, but their nursemaid, Galene, was screaming in a hideous storm of foreign frustration. Albia had refused assistance. Currendy she was locked in her room. She was a teenaged girl; Helena let her act like one. Nux was in hiding with Albia. We tapped at the door and called out that we had to go somewhere. 'Get going then!' snarled Albia from within. Well, it was better than 'I hate you', and much better than 'I hate myself. In about six months we would be facing both.

We sent Galene to the kitchen, telling her to make good use of it and cook something. Jacinthus was there, but unlikely to be productive. Galene bounced off happily. Helena looked rueful. 'Maybe we should just accept this, Marcus.' 'Right. First step to degeneracy: be ruled by your slaves.' We put our daughters into cute little matching tunics with bows in their hair and took them with us. Anyone who wants to offer a better solution can just keep quiet. 'What extremely advanced parents!' Claudius Laeta hooted with disdain. 'Your soldiers have disrupted my quiet household routine,' retorted Helena.

Laeta said he would be happy to remove the soldiers – when I earned my fee and found Veleda. Feigning anxiety, Helena and I relaxed. Julia and Favonia sat on our laps as good as gold, fascinated by riding in the litter. If Laeta took us anywhere with slaves, we were sure of a welcome for these deceptively sweet cupids.

I had assumed the conference was in the Palace. Instead, I soon realised we were going down the Via Aurelia; Laeta admitted we were going to the villa of Quadrumatus Labeo. 'One of his Saturnalia guests needs a progress report.' 'We answer to Quadrumatus?' I snorted with astonishment. 'Not him.' Laeta lost some of his pomposity. 'Out-of-town is more discreet, Falco.' I let Laeta deal with the bloody-minded Lusitanian doorkeeper.

While he struggled to declare his invited status and the porter sneered at that idea, Helena wiped up Favonia's dribble. Although I had kept a close grip on Julia, she had managed to get black door hinge oil on her; I dealt with that by the time we carried them indoors, where entranced slave girls fell on them. After hardly any training from us, my children both knew how to gaze at strangers with big appealing eyes. 'Don't give them any food!' I ordered sternly, as Scaeva's ex-girlfriends carried them off in delight.

They took the hint. 'Oh the dear little things must have some must cake to celebrate the festival!' Good. It was bound to be made properly here, with wine-lees from the estate. After running around the peristyles playing hide-and-seek with the sewing girls, mild intoxication would work magic. Our little monsters would be fast asleep when we collected them.

There were plenty of grand ladies on whom Julia and Favonia could practise their techniques of begging for jewellery and toys, for the place was full of stiffs, and since it was Saturnalia, the stiffs had brought their stately wives. The Quadrumati were bravely putting bereavement behind them and going ahead with their annual house party. 'Invitations will have been sent months ago,' Helena sneered. 'And the hospitable Quadrumati would not want to disappoint their many friends.' 'I seem to recall Quadrumatus asserting "We are a very private family"! Yet half the Senate have congregated, in the hope of blood on the marble.'

'Marcus, I bet most of them will slip a servant a denarius to sneak them into the crime scene.' Apart from the fact they looked a mean bunch who would think a whole denarius was too much, Helena was bound to be right. Snobs are the worst gawkers. It explained why the Quadrumati had tried to hush up what happened.

Laeta bustled off importantly to see where the meeting would be. We moved among the milling groups of notables, marvelling that none of the family was anywhere in evidence.

'Entertaining the fashionable way,' Helena enlightened me. 'You invite hordes of people, whom you know only slighdy, then you keep out of sight but let them wander at will admiring all you own.' 'Giving them a good shake-down for stolen silverware when they leave?' 'I suppose the message is that the hosts have so much money, Marcus, that even if everybody steals something, they won't miss it.'

We worked out that the gathering was mixed, in fact. We identified various off-duty hired entertainers, and Drusilla's troupe of dwarfs were stomping about being offensive. They were all drunk. Perhaps they knew where Drusilla kept her wine stash. The men the dwarfs were insulting seemed to be tradesmen. Although it was still mid-morning, they were digging into trays of pre-lunch snacks and aperitifs; perhaps it was the only way they could guarantee themselves a Saturnalia bonus. Of course the senators ignored them, and the tradesmen were even more snobbish about sticking together and not conversing with the senators. While such a melange could appear egalitarian, Helena and I thought that the groups had just been bunged together in a perfunctory and rather tasteless manner. 'It makes you wonder what they would have done with Veleda,' said Helena. 'I suspect they would have let everyone know they had her – and made her a sideshow.' Among the retainers who had gathered to grab festive gifts, we found a knot of medical specialists. Aedemon's bulk made him instantly visible; he was talking to a man 1 remembered as Pylaemenes, the Chaldean interpreter of dreams in his shabby robe. 1 would have ignored them, but 1 spotted Anacrites nuzzling up to them. He must be here for the same meeting as me. When 1 walked Helena over to see what he was up to with the physicians, 1 also recognised the third man. He was Cleander, who on my previous visit had turned up for a consultation with Drusilla Gratiana. He had an oval face, round eyes, and a restrained manner which probably meant he could be savage if he fell out with anyone. 'Name's Falco. We passed in a doorway. You look after the lady of the house.' 'And you're the bloody sleuth.'