Tiro set the tray on a low table between us. Cicero glanced at it without interest. 'So much food, Tiro?'

'It's almost midday, Master. Gordianus will be hungry.'

‘Very well, then. We must show him our hospitality.' He stared at the tray, hardly seeming to see it. He gently rubbed his temples, as if I had stuffed his head too full of seditious ideas.

The walk had made me hungry. The talk had left my mouth thick and dry. The heat had given me a deep thirst. Even so, I patiently waited for Cicero to initiate the meal — my politics may be radical but my manners have never been questioned — when Tiro gave me a start by leaning forwards eagerly in his chair, tearing a piece from a loaf, and reaching for a cup.

At just such moments one learns how deeply convention is bred into the soul. For all that life had taught me about the arbitrary nature of fate and the absurdities of slavery, for all that I had endeavoured from the moment I met him to treat Tiro as a man, I still let out a quiet gasp at seeing a slave take the first food from a table while his master sat back, not yet ready to begin.

They both heard it. Tiro looked up, puzzled Cicero laughed softly.

'Gordianus is shocked He's not used to our ways, Tiro, or to your manners. It's all right, Gordianus. Tiro knows that I never eat at midday. He's used to beginning without me. Please, eat something yourself. The cheese is quite good, all the way from the dairy at Arpinum, sent with my grandmother's love.

'As for me, I'll have a bit of the wine. Only a bit; in this heat it's likely to turn sour in the stomach. Is it only me who suffers from that particular malady? I can't eat at all in midsummer; I fast for days at a time. Meantime, while your mouth is busy with food instead of treason, perhaps I'll have a chance to say a bit more about my reasons for asking you here.'

Cicero swallowed and gave a slight wince, as if the wine had begun to sour the moment it passed his lips. 'We strayed from the subject some while ago, didn't we? What would Diodotus say to that, Tiro? What have I been paying that old Greek for all these years if I'm not even able to hold an orderly conversation in my own home? Disorderly speech is not only unseemly; in the wrong time and the wrong place it can be deadly.'

'I was never quite certain what the subject was, esteemed Cicero. I seem to recall that we were plotting to murder someone's father. My father, or was it Tiro's? No, they're both already dead. Perhaps it was yours?'

Cicero was not amused. 'I introduced a hypothetical model, Gordianus, simply to sound you out about some factors — methodology, practicality, plausibility — regarding a very real and very deadly crime.- A crime already accomplished. The tragic fact is that a certain farmer from the hamlet of Ameria—'

'Much like the hypothetical old farmer you described?'

'Exactly like him. As I was saying, a certain fanner from Ameria was murdered in the streets of Rome on the Ides of September, the night of the full moon — almost eight months ago. His name you already seem to know: Sextus Roscius. Now, in exactly eight days — on the Ides of May — the son of Sextus Roscius will go on trial, accused of arranging the murder of his father. I'll be defending him.'

‘With such a defence I should think there'd be no need for a prosecutor.'

'What do you mean?'

'From all you've said, it seems obvious that you think the son is guilty.'

'Nonsense! Was I that convincing? I suppose I should be pleased. I was only trying to paint the case as his accusers might describe it.'

"You're saying that you believe this Sextus Roscius is innocent?' 'Of course! Why else should I be defending him against these outrageous charges?'

' Cicero, I know enough about advocates and orators to know that they don't necessarily have to believe in a point to argue for it. Nor do they have to believe in a man's innocence to defend him.'

Tiro suddenly glowered at me across the table. ‘You have no right,' he said, with a desperate little break in his voice. 'Marcus Tullius Cicero is a man of the highest principles, of unquestionable integrity, a man who speaks what he believes and believes every word he speaks, rare enough in Rome these days perhaps, but even so—'

'Enough!' Cicero's voice carried tremendous force, but little anger. He raised his hand in an orator's gesture of desist, and seemed unable to keep from smiling.

'You'll forgive young Tiro,' he said, leaning towards me with an air of confidentiality. 'He's a loyal servant, and for that I'm grateful. There are few enough to be found nowadays.' He gazed at Tiro with a look of pure affection, open, genuine, and unabashed. Tiro suddenly found it convenient to gaze elsewhere — at the table, the tray of food, the softly billowing curtain.

'But perhaps he is sometimes too loyal. What do you think, Gordianus? What do you think, Tiro — perhaps we should pose such a proposition to Diodotus the next time he calls and see what the master of rhetoric can make of it. A fit subject for debate: is it possible that a slave can be too loyal to his master? That is to say, too enthusiastic in his devotion, too ready to spring to his master's defence?'

Cicero glanced at the tray and reached for a bit of dried apple. He held it between his thumb and forefinger and studied it as if considering whether his delicate constitution could tolerate even such a tiny morsel in the full heat of the day. There was a pause and a silence, broken only by the trilling of a bird in the atrium outside. In the stillness the room around us seemed to breathe again, or rather to attempt to breathe, vainly struggling to catch a shallow breath and coming up short; the curtain billowed tentatively inward, then out, then in again, never quite enough to release a gust of air in either direction, as if the breeze were a warm and palpable thing trapped beneath its brocaded hem. Cicero frowned and replaced the morsel on the tray.

Suddenly the curtain gave an audible snap. A breath of warmth eddied across the tiles and over my feet. The room had finally released its pent-up sigh.

'You ask if I believe that Sextus Roscius is innocent of his father's murder.' Cicero spread his fingers and pressed the tips together. 'The answer is yes. When you meet him, you too will believe in his innocence.'

It seemed at last that we might be getting down to business. I had had enough of the games passing back and forth in Cicero's study, enough of the yellow curtain and the stifling heat.

'How exactly did he die, the old man? Bludgeons, knives, stones? How many assailants? Were they seen? Can they be identified? Where was the son at the very moment the crime took place, and how did he learn the news? Who else had reason to kill the old man? What were the terms of his will? Who brings the charges against the son, and why?' I paused, but only to take a sip of wine. 'And tell me this—'

'Gordianus,' Cicero laughed, 'if I knew all this, I would hardly be needing your services, would I?'

'But you must know a little.'

'More than a little, but still not enough. Very well, I can at least answer your last question. The charges have been lodged by a prosecutor named Gaius Erucius. I see you've heard of him — or has the wine turned to vinegar in your mouth?'

'I've more than heard of him,' I said. 'From time to time I've actually worked for him, but only from hunger. Erucius was born a slave in Sicily; now he's a freedman with the shadiest law practice in Rome. He takes cases for money, not merit. He'd defend a man who raped his mother if there was gold in it, and then turn around and prosecute the old woman for slander if he saw a profit. Any idea who's hired him to take on the case?'

'No, but when you meet Sextus Roscius—'