Glaucus admitted a certain quiet class. Some, like me, had professional reasons for wanting to train. Others just preferred the refinement of a place where rowdy or crass social monsters were barred. There were no loud voices, no roistering inebriates – and no oily bastards looking out for pretty boys either. There was little room for spear-throwing, but wrestling and swordplay were available. For a steep fee, Glaucus would give you a lesson that was almost as uncomfortable as being ridden down by murderous tribesmen galloping on wild horses – or you could relax in a small courtyard and read poetry. There was even a library, though nobody much used it. You could find a delightful young lady to trim your fingernails, or buy an excellent pastry adorned with toasted pistachio nuts. Perhaps the manicurist offered extra services, but if so, she didn't push it; I always settled for a nutty slice instead, believe me. I doubt if the senator even had that; his wife was making him watch his weight.

We bathed. Decimus usually had a slave to scrape him down, and today so did I. I stood lost in thought, while the boy expertly plied the strigil. Afterwards, Decimus swam in the tiny pool. I never did, though I carried out a few exercises, continuing after my companion hauled himself from the freezing water and huddled in a robe while he chatted to Glaucus.

`Your name is on a lot of lips,' said Glaucus, when I joined them. He disapproved. So did I. Fame may be attractive to many, but in my trade it is an encumbrance. Informers should keep anonymous.

`People will soon forget.'

`Depends what kind of fool you make of yourself, Falco.' My trainer never reckoned to keep his clients with flattery.

`Oh I'll be the usual fool,' I admitted.

He laughed harshly. `That's all right then!'

The senator had finished drying off and pulling on tunics. At sixty plus, he kept himself well layered up in winter. He hauled me to the library; now I knew what it was there for: plotting. Glaucus had arranged to have a brazier sent in. Snacks and wine followed.

`Should I fetch my note-tablet?' I wondered.

`Better not.' The mood was now distinctly sombre. It had nothing to do with winter's early darkness closing in. `Marcus, you'll prefer not to write down what I tell you.'

I settled on a reading couch. `And what,' I asked, still slightly askance, `will that be, Decimus?'

`All I know,' replied Helena's father quietly, `about the past careers of Silius Italicus and Paccius Africanus.'

My jaw dropped. `You can give me some dirt?'

`Remind you, maybe. It came up in the Senate.'

`I confess I don't recall either of them featuring.'

`Well, I was there. So that helped it stick. It was in the early sessions, when Vespasian first became Emperor.' Decimus paused slightly. `Had things worked out differently, I might have hoped to benefit from the accession. So I was a regular in the Curia – and it was riveting.' We both looked pensive. Camillus Verus had been destroyed politically, around that time, through the actions of a relative. He lost out on what could have become a big career; five years later, the taint still badly damaged him and his sons.

He rallied and continued: `Young Domitian was still presiding in his father's name; this was before he went too far and had his wings clipped.' Vespasian and his elder son Titus preferred not to dwell on the early career of Domitian. In fairness, the Emperor's younger son was only twenty at the time, representing his father five years before he would normally have been an acceptable face in the Senate. `This is dangerous material. I cannot advise you how to handle it, but Marcus, I'll do my best to give you all the history.'

I was impressed by the fact that Camillus had brought me here, rather than contaminate either of our homes with what he had to say. He was a man of curious refinement.

As I said, the library was rarely used. Tonight I thought that was just as well. It would not do for others to know we had held this conversation.

We spoke for a long time, until I was well rehearsed.

Afterwards, I returned home silently, my head thronging with ideas. Helena accepted my stillness. Maybe her father had hinted at how he intended to brief me.

None of what he told me was a secret. Six years ago I had despised the Senate and jeered at its day-to-day proceedings. Maybe I read about the relevant debates in the Daily Gazette columns, but it had little impact at the time. We were awash with news then. Vespasian's accession had come at the end of a long period of lurid events. Evaluating every one was impossible. Our main concern had been that the civil wars and city famine should end, along with street fighting, fires, destruction and uncertainty.

That night, I could not decide what to do. I was nervous about using this hot material in open court. I talked to Helena; she encouraged me to be bold. Some members of our jury would have been present when the debates happened, after all. Dragging up old sensitivities was dangerous, however. I would be reviving a political scandal, which in a highly political city is always sinister.

I slept all night. Long training helped. I was still undecided when I left home with Helena next morning. But as soon as I walked into the Basilica, saw the long rows of the jury and felt the hall humming, I knew: this was risky – but too good to ignore.

I glanced up at the upper gallery. Peeking around the corner of a curtain, Helena Justina read my thoughts and smiled at me.

The Accusation against Calpurnia Cara: M. Didius Falco on C. Paccius Africanus

My young colleague Honorius spoke to you yesterday with great eloquence. I have been impressed by his setting-out of the issues. I congratulate him on the way he has addressed difficult material. In describing Calpurnia Cara's predicament, he has been most even-handed, while never forgetting the demands of justice for a terrible crime.

Since he has done such an excellent job so far, you may be wondering why we have decided that I should address you on the next subject. Honorius is of senatorial rank, a promising advocate, who will without question make a fine career in both the special courts and the Senate itself. Gentlemen, having made such a start, he is eager to conclude the business before you; it is indeed hard for him now to hand over to me. He has stepped back because I have particular insight into a certain type of person who may have influenced the accused.

My name is Marcus Didius Falco. I am of equestrian rank, a position for which I have to thank the personal interest of the Emperor. Some of you – and our most excellent judge, Marponius, who knows me well – will be aware that this is by no means the first time I have appeared before the murders court. I have made it a habit to identify killers and bring them to trial. I have had some success. If I were to explain myself for the benefit of those who do not know me, I would say I make it a speciality to investigate wrongs which are not suitable for the vigiles or for which the hard-pressed vigiles lack immediate resources. Sometimes I have been commissioned officially for enquiries in the community, and I may say to you that on occasions, my commissions came from the highest level. By its nature, I may not discuss that work. I mention it only so you may appreciate that people of shrewd judgement in powerful positions, the Emperor's closest advisers in fact, hold my services in some regard.

Why am I talking so much about myself? Because of this: my profession, if I may boldly call it that, is that of the informer. I hardly know how I can have named it – for informing is so often a term of abuse. If we were to go out into the Forum Romanorum now this minute, and ask passers-by to define informers, I believe their answers would include: immoral patricians, men who are intent on rising rapidly despite lack of personal talent, men without principle, and lowborn toadies hanging around the skirts of power. They might describe vicious ambition and pitiless manoeuvring. They might suggest that informers target victims for their own benefit, under cover of serving society by cleaning it up. They would undoubtedly complain about men who leap from extreme poverty into questionable wealth, men of insignificance who acquire inexplicable prestige. They would say that informers ruthlessly attack their victims, using means that are often of doubtful legitimacy. Worst of all, remembering the excesses and abuses under emperors like Nero, a creature now 'damned to the memory' for his appalling crimes, people would fear that the role of informers may be still that of secret, subversive informants, whispering poison in the ear of the Emperor.