`The patrol couldn't hold him back,' Fusculus told me. `The door was ajar. As soon as Scythax saw the situation, he was in like an, arrow, howling and covered with blood himself. They had a terrible time dragging him away from Alexander and getting him back here. He still keeps trying to return to the surgery.'

Everyone present was white-faced. There was plenty to do, but they were sitting together in the patrol house, impotent. They saw violence daily; hideous death far too frequently. This had struck too close. This affected one of them. This – though nobody had yet mentioned it – was something their own work had caused. Alexander might have been attacked by a deranged patient, but we all thought this was directly related to his false diagnosis of Nonnius Albius.

We spent a day trying to make sense of it. First we all said there was no point going to look at the surgery – or no point all of us going. We all went. It seemed a gesture of respect. We had to force ourselves to see what the man had endured. Petronius imposed it on himself as a punishment. Some of the others made it serve as an apology. I went because I knew from experience that if you don't, you never stop worrying whether there was some clue you could have spotted if you had been there. We badly needed evidence. The squad was so shaken up that any clues there were might easily be missed or misinterpreted.

Young Porcius was the only one who actually vomited. The scene knocked back his composure completely; there was nothing for it but to send him to the station house to sit with Scythax again. By the end of the day the youngster was a gibbering wreck, but we had too much else to think about. He was given sympathy, but no one could nursemaid him.

`The chief's heartbroken,' Martinus muttered at me. Even he had lost all his cockiness.

`I've never seen him so bad,' Fusculus agreed dolefully.

I was his friend. They all seemed to want to tell me about Petro's distressed state. I could hardly bear it. I needed nobody to tell me. He was as foul-tempered as I had ever seen him – except once, during the Boudiccan Rebellion in Britain. He was older now. He knew more obscene words, and more painful ways to take out his anger on people nearby.

I would have hauled him out for a drink, but the mood he was in he would have stayed knocking it back until he passed out or killed himself.

By the afternoon we had exhausted ourselves asking questions. Several innocent householders had gone off to complain to the Prefect's Office about the way they had been pushed around and bawled at. Nobody had seen or heard anything suspicious, either last night or the previous day. Nobody knew anything. Nobody wanted to know. Everyone had caught a whiff of gangster involvement. Everyone was terrified.

We all believed the same people had killed both Alexander and Nonnius. Even that simple fact was hard to prove. The evidence denied it. One victim had been abducted; one was killed at home. One was a declared informant; the other had been sensibly discreet. The methods used were completely different. The message sent out seemed less flagrant the second time. Apart from the fact both murders happened at night – like most crimes in Rome – only the violence inflicted was common to both. Only instinct and experience convinced us we were right to link the two deaths. But it all made sense if we decided that Nonnius had been killed as an act of revenge for betraying Balbinus, and Alexander had died because someone found out it was him telling Nonnius he was dying that- had led to that villain's `reform'.

The public baths were opening by the time the investigation broke up for the day. The scent of wood smoke on the damp October air gave an autumnal gloom and added to our melancholy mood. We were no further forward. There was a sense that we would spend this coming night waiting for more deaths. We were losing. The villains had all the dice running for them.

With a set face, Petronius ordered the body's removal – to an undertaker this time, not the station house, where the dead man's distraught brother was still being looked after. He then arranged for members of the foot patrol to be brought in to clean up and 'leave the surgery neat. Fusculus volunteered to oversee that. He seemed to need something to fill his time. Petro thanked him, then sent the rest home.

I saw Petronius to his house. He said almost nothing as we walked. I left him at his door. His wife let him in. She glanced at his drawn features, then her chin went up, but she made no comment. Maybe she even gave me a half-concealed nod. Arria Silvia loved to rant, but if ever Petro looked beaten she rushed to protect him. So Silvia took over, and I was not needed. As the door closed, leaving me alone in the street, I felt momentarily lost.

It had been a terrible day. I had seen Rome's underbelly, smelt the matted filth beneath the ravening wolf. It was nothing new, but it forced me to face the lack of hope that lives alongside crime. This was the true face of the Caesars' marble city: not Corinthian acanthus leaves and perfect gilt-lettered inscriptions, but a quiet man killed horrendously in the home and workplace he shared with his brother; a vicious' revenge thrust on the onetime slave who had learned a respected profession then repaid his freedom and citizenship with a single act of assistance to the law. Not all the fine civic building programmes in the world would ever displace the raw forces that drive most of humankind. This was the true city: greed, corruption and violence.

It was dusk as I made my way to Fountain Court. My heart lay heavy. And for me, the day was nowhere near over yet. I still had to put on a smile and a toga then go out to dinner with my girlfriend's family.

XLIII

ONCE WE GOT past the porter, who had always viewed me like a door-to-door lupin seller who was aiming to snatch silverware, it was an occasion to remember. The hosts were so considerate that guests felt free to behave badly. Helena Justina's birthday, in the consulship of whoever it was, laid the foundation for many happy years of family recrimination. For once, it was not my family involved.

Being a mere private citizen, my manners were the best on display. As soon as I escorted Helena from the carrying chair I had grudgingly hired, I turned to find her mother right behind me waiting to knock me aside and embrace the birthday girl. I kissed the matron's cheek. (smoothly oiled and scented) with grave formality. She was a tall woman who had not expected me to tackle her, so the manoeuvre required dexterity. She was even more surprised than I was.

`Julia Justa, greetings and thanks. Twenty-five years ago today you gave the world a great treasure!' I might not be the ideal son-in-law, but I knew how to press a rather nice soapstone casket of balsam into a lady's receptive hands.

`Thank you, Marcus Didius. What a pretty speech.' Julia Justa was a mistress of elegant hypocrisy. Then her expression froze. `Why,' queried Helena's mother icily, `is my daughter carrying a child?' Helena had brought the skip babe.

`Oh Marcus found him in a rubbish skip!' cried Helena Justina breezily. `But there's another child I'm carrying that you'll want to hear about.'

This was hardly the tact and decorum I had tried to plan. On the other hand, nobody could say that it was my fault.

I had a side bet with the Fourth Cohort that the night would end with women in tears and men losing teeth. (Or the other way round.) Before we even crossed the threshold there was some jostling for position among the female element.

Helena's mother wore leaf-green silk with an embroidered stole; Helena wore not merely silk, but a fabulous cloth from Palmyra woven in multiple patterns of purple, brown, deep red and white. Helena's mother wore an expensive parure of golden scrolls and droplets set with a clutch of evenly matched emeralds; Helena wore an armful of bangles, and absolutely enormous Indian pearls. Helena's mother was scented with highly refined cinnamon perfume, the one Helena herself often wore; Helena tonight wore a few vivid dabs of a precious liquor containing frankincense. She also had the gracious air of a daughter who had won.