In our case there seemed little need for sightseers to hang over the balcony rails; a few friends and members of the public lounged on seats we had supplied, but standing room was hardly at a premium. The Basilica staff had allocated us a derisory area at one end of the huge hall. A single usher waved us in with obvious lack of interest. We greeted well-wishers hoarsely. It did not take long.

We watched Marponius strut into the Basilica Julia, followed by an official slave who carried his folding ivory stool, and a slave of his own who had brought him an unofficial red cushion to slip on to it. Marponius had a very well padded backside, which gave him a strange walk and an uneven toga hem. He had a bald crown with curly side panels, all covering what Petronius and I denounced as only half a brain. The wrong half.

He gave a cool nod to Petronius, who was backing me up on the first day in court. I received a blank stare, though that may have been because I was sporting a large assisted bruise that gave me the appearance of a mad-eyed painted statue where the artist had wanted to use up all the pigment on his palette to save cleaning it. Honorius sat between me and Aelianus; Justinus had so far failed to return from Lanuvium. Despite his previous court experience, Honorius was extremely quiet. I found it more and more worrying.

The accused entered stiffly, as if to emphasise her years. Not quite limping, but walking with some awkwardness, Calpurnia took her place between the gloomy-looking, overweight Silius and the saver, slimmer Paccius. She had disdained to dishevel her clothing to win sympathy, though she did wear her long grey hair loose; it was caught under the matron's stole she wore tightly wrapped around her body. She had no visible jewellery, perhaps because she had sold it all. Her expression was thunderous. Her son was in court, but she never looked at him. Negrinus never looked at anyone.

Marponius took it upon himself to address the jury on their duties and the legal teams on how he wished to run his court (he phrased it another way but he meant, with both legal teams subservient to him as he rode roughshod over them). Then we began. First came the prosecution's opening speech, in which the charges would be set out. Honorius was to deliver this. As he rose, Paccius and his old senior Silius smiled tolerantly to disconcert our young man. He took it well. Adjusting his toga briefly for the best effect, and revealing little of the nerves I suspected he felt, Honorius began:

The Accusation against Calpurnia Cara: Speech for the Prosecution by Honorius

Gentlemen of the jury, this is a case in which a noble family come to ruin tragically. Founded in Lanuvium, the Metellus family has old roots and old money. They have been senators for five generations, serving Rome with honour and distinction. The present generation appeared to flourish and live happily for thirty years. The daughters married well and left home. The son married and stayed with his parents. All had children. The son was progressing through the senatorial ranks, and if not a star, he was securely fulfilling his ambitions. About two years ago, something happened.

I admit to you freely, it is not yet clear what the disaster was. Perhaps Calpurnia Cara will shed light on it. One thing is certain: this event was catastrophic. Lack of money became a problem. The father and son desperately sought to increase their funds through corruption. The father wrote a savagely unjust will. His family were then beset from all sides.

Let me list their enemies: An informer called Silius Italicus, whom you see in court today, laid formal corruption charges, in a case which he won. The son's wife, Saffia Donata, turned against her husband and, he says, stripped him of everything. Another informer who sits among us here, Paccius Africanus – with or without connivance from Silius-moved in on the family with motives that may have seemed helpful at the time but which now look only sinister. At least one of their slaves, a door porter, Perseus, seems to have discovered secrets they wanted to hide, and ran rings around them. And harboured in their midst was Calpurnia Cara, apparently a devoted wife and mother, but as we shall show you, a woman of strong passions and determined hatreds, who would not flinch from the worst possible action.

Following his condemnation in the court case, Rubirius Metellus was advised to commit suicide. This did not suit the informer who had accused him of corruption, for if the condemned man took his own life, Silius would lose his compensation. To the dismay of Silius, Metellus died. From motives we can only despise, the informer rallied; next he accused the elder daughter of poisoning her father, after Metellus had allegedly declined to take his own life. Rubiria Juliana was tried in the Senate, but was acquitted and lives blameless. Thwarted, Silius Italicus has now allied with his colleague, Paccius Africanus, to accuse the son instead, in a case which has yet to be heard. Truly, the children of the late Rubirius Metellus carry a heavy burden. It weighs worst on the son. Disinherited by his father, for reasons of which he is totally ignorant, he now learns he has a brazen and callous mother. The unnatural woman whom we have brought before you intends to give evidence that will condemn Metellus Negrinus, her only son, for his father's murder.

We, however, will be able to demonstrate that it was not the ill-fated Negrinus who killed his father – but his mother Calpurnia Cara. She may have been a blameless wife – certainly she will tell you so. You will be shocked by what drove her to the dreadful crime she committed. She had had to endure a husband who exhibited, in the most public way, a shameful partiality for his own daughter-in-law. That young woman has unfortunately died in childbed this very week and cannot be questioned. But her influence on Rubirius Metellus is demonstrated by the way he treated her financially and it is the root cause of this family's misery. The rapacious and blackmailing demands of the daughter-in-law led to an unenviable need for money, which resulted in the corruption for which Metellus was found guilty. And the unnatural favour shown to his daughter-in-law in his will led to his death at the hands of his embittered wife. You may feel sympathy for her predicament, but her unflinching dispatch of her husband and her desperate measures to conceal the crime deserve only condemnation.

Fuelled by sorrow, shame, and anger at her omission from the will of a husband of near forty years, Calpurnia Cara turned on Rubirius Metellus and removed him from the world. We shall show you that she sold her jewellery, then consulted a woman familiar with the black arts, to learn what fatal poison she should choose and how it might be administered. She arranged to obtain the noxious drug, through the medium of Paccius Africanus – a man who must be no stranger to the disreputable side of life. They used one of his creatures, a man of such appalling habits that he has employed violence on the very streets of Rome in a foolish attempt to dissuade us from bringing this case. You can see sitting there, my colleague Didius Falco, still bearing the scars of that vicious attack.

Calpurnia arranged to have the chosen drug, insidious hemlock, secretly given to her husband in his lunchtime meal. Metellus succumbed, and far from committing suicide among his loving family as the world was informed, he may have died a lonely death. Certainly his corpse was accorded no respect. Calpurnia attempted to hide the results of her actions by concealing the body; Metellus may not even have been dead when she secreted him in a crude garden shack – but it was in that sorry place that he met his end. For three whole days the body of Rubirius Metellus lay concealed in that mean location, without the honours due to a man of his rank or the sorrowing ministrations of his children and his friends. Neither his children nor his friends were aware of what had happened.