‘Do you see more clearly now?’ Caligula leaned forward. ‘You were married to my sister! You shared my bed! Garrotte him!’

Castor slipped the noose over Lepidus’s shaking head. He took a small tube out of his belt and expertly turned it. We all had to sit and watch whilst Lepidus died with terrible, choking gasps. Occasionally, Caligula asked the German to stop so he could give the half-dead man a stern lecture on morality. The torture continued. A full nightmarish hour passed before Lepidus’s corpse was allowed to fall slack onto the floor. His face had turned purple-black, and blood seeped from the hole where his eye had been.

Caligula raced round, shaking his fingers at the guests. He gestured with his fist at Afer the orator.

‘You should have known better! You are going to answer for your treason in the Senate!’

Others were present, bankers and merchants who had been on the fringe of the conspiracy. The guests also included some innocent neighbours from surrounding villas. Caligula showed no mercy. One by one they were taken out to the garden and despatched by the waiting soldiers. Some were decapitated — Caligula shouting that one man’s head should be pickled and brought back immediately — others were strangled, and a few shackled and bundled into a cart for transport back to Rome.

Agrippina sat throughout the horror as immobile as a statue. Caligula turned on me and clicked his tongue, imitating Sejanus.

‘I’ll deal with you personally, Parmenon.’

He rose, gave Lepidus’s corpse a vicious kick and led me out through the colonnades into the garden. That place of beautiful serenity had been transformed into a flesher’s yard. Corpses lay about. A decapitated head had rolled to rest behind a seat. Pools of sticky blood glistened in the moonlight. Caligula ignored all this as, hand on my shoulder, he went across to sniff at a rosebud.

‘Beautiful,’ he murmured, closing his eyes. ‘Such smells always takes me back to Capri and the old goat. Well, well, Parmenon, what a pretty mess, eh? What shall it be for you? Crucifixion? The garrotte? Or shall I stick your head on a pike?’

His face was solemn till he burst out laughing and punched me playfully in the stomach.

‘I’m only joking,’ he declared. ‘You knew my spy was Progeones, didn’t you?’

I nodded.

‘And if he hadn’t told me, you would have, wouldn’t you?’

‘Yes,’ I lied.

‘I can’t kill you, Parmenon. You’re my lucky mascot. But what — ’ his face turned ugly ‘- am I to do with that bitch of a sister?’

‘Your Excellency.’ I swallowed hard to prepare the biggest lie in my life. ‘Your Excellency, it’s true she’s a dangerous bitch but. . she is your sister and that of Drusilla.’

‘True, true.’ Caligula sat down on a garden wall and dropped his lower lip. ‘By the way, where’s that slut Julia? She’s involved as well, isn’t she?’

‘Of course, your Excellency.’

‘Now what were you saying about Agrippina?’

‘She’s a dangerous bitch, your Excellency, and she’s also a blackmailer. She claims to have documents proving you are not Germanicus’s son. If she dies,’ I continued coolly, ‘these are to be released to the Senate.’

Oh, it was a terrible gamble. Caligula was mad. He could have either exploded into rage or returned to the behaviour which had kept him safe on Capri. I wasn’t disappointed. He positively cringed, fingers going to his mouth. I suspect Tiberius had often taunted him with the same jibe. He gnawed furiously at his nails.

‘The filthy bitch!’ he murmured. ‘Is this true, Parmenon? I can have you tortured.’

‘Torture me, Excellency, your lucky mascot. I tell the truth, you know I do. I think Tiberius told her. He had proof, didn’t he? Some filth dug up by Sejanus?’

Caligula was not listening. He turned, speaking to that mysterious invisible presence beside him: a litany of curses and filthy epithets about Agrippina, his own mother, Tiberius and Sejanus.

He paused. ‘What do you suggest, Parmenon?’

‘Be careful, Excellency.’ I knelt down on the ground before him. ‘You are both Emperor and a God. Death is too quick. Separate her from her beloved son.’

Caligula gave a great sigh.

‘Kill him instead, you mean?’

‘No, no,’ I hastened to add. ‘Give her son to someone she hates.’

‘I’ll do that. And the bitch?’

‘Exile her. Not too far away so she’ll know what goes on in Rome.’

Caligula agreed. ‘I’ll have to talk to the Gods about this. But come, come, Parmenon, the punishment must be more than that.’

‘Have her depicted as Lepidus’s lover,’ I continued.

‘Good!’ Caligula held his hand up. ‘That’s very good, Parmenon. I also want the names of all the other traitors involved in this plot, and something else.’ He glared round at the corpse. ‘When Mother returned to Rome she brought the ashes of my father,’ — he emphasized the words, — ‘my father Germanicus, into Rome. Well, she can do the same.’ He bawled for the captain of his guard. ‘Take Lepidus’s corpse!’ he ordered. ‘Have it burnt. I want the ashes poured into the cheapest vase you can find.’

The man hurried away and returned dragging Lepidus’s corpse by the heels. Some of his companions brought out items of furniture and a makeshift funeral pyre was made, before it was drenched in oil and Lepidus’s corpse tossed onto it. Caligula watched until the cadaver caught light.

‘I can’t stand the smell of burning flesh!’ he pouted. ‘It always makes me sick, whilst the sound of bubbling fat. . Ugh!’ He wafted a hand in front of his nose. ‘Well, I’ll go and look at the other prisoners.’

He walked away, then whirled round.

‘Oh, Parmenon, I haven’t forgotten you. You must follow your mistress into Rome and then join her in exile. You’ll be allowed to return to the city three, no, four times a year, so the bitch can get all the news.’

Off he strode. To my right Lepidus’s body was now engulfed in flames, black billowing smoke and a filthy stench. From the villa came the sound of screams and crashing, as Caligula’s bodyguards helped themselves to the slave girls. I hurried back inside to find Agrippina still sat on the couch, white-faced, tense but ready for death. I told her quickly what I had said to Caligula. She listened hollow-eyed.

‘Where there’s life,’ she whispered. ‘There’s hope.’

She stroked my cheek and then, if I hadn’t caught her, would have crashed into a dead faint onto the floor.

Five days later Agrippina, bare-footed, dust strewn on her hair and clothed in a simple tunic, walked into Rome bearing a chipped urn containing Lepidus’s ashes. She accepted her fate philosophically, more concerned about being deprived of her beloved Nero than any public humiliation. I was forced to walk behind, carrying a cushion bearing the three daggers Agrippina had bought for Caligula’s murder. Praetorian guards forced a way through the jostling crowds assembled on the streets. I was aware of shouts, of strange pungent smells; spice, sulphur, the foul odours from the cesspits and sewers. The black ravens, flocking to the graveyards to pluck at those corpses not properly buried, seemed everywhere. A fire had been lit and its smoke billowed about. The slums disgorged their inhabitants who were only too eager to watch the spectacle of one of the great ones who’d fallen lower than themselves.

Yet there was no jeering, no catcalls, no abuse. People recalled Agrippina’s father, how her mother had brought his ashes back to Rome in a similar but more honourable procession. The senators, the knights and the merchants were also wise enough to know that fortune’s fickle wheel can be spun at the touch of a hand. Today Agrippina was in disgrace but tomorrow. . who knows? Moreover, Caligula was hated and feared. Here was a woman who had dared to confront him. There was grudging respect and admiration. Indeed, by the time we had left the winding, narrow streets onto the Via Sacre leading to the Palatine, the atmosphere had imperceptibly changed. At the time I was only aware of that cushion which seemed to weigh as much as a rock, of the sweat pouring down me and of the tall, elegant figure of Agrippina, walking in front. She carried the urn with her head held high, gaze fixed before her, looking neither to the right nor the left. We climbed the Palatine hill, on which flowers and grass were strewn as if to protect her naked feet. The commander of Caligula’s bodyguard, a Thracian, realising that this was not the disgrace Caligula had intended, urged her to move faster. If anything, Agrippina walked slower.