‘Come on!’ she urged. ‘Sit here! I won’t bite you.’ She grinned mischievously. ‘Yet!’

I took a step forward.

‘No, first open the door, quickly! See if anyone’s in the corridor outside.’

I obeyed but the gallery was empty. Dust motes danced in the pale afternoon sun which streamed through one of the high windows. I closed the door.

‘Again!’ Agrippina whispered. ‘Open the door quietly and look down! Do it quickly, quietly!’

I obeyed but still saw no one there. I closed the door and she beckoned me over. I sat on the edge of the couch and stared down at her. She looked even more beautiful: her eyes had turned a dark blue, her skin had the sheen of porcelain, her lips seemed fuller and redder. I wondered what it would be like to kiss her.

‘If Livia was still alive,’ she murmured, pulling herself up and resting on her elbow, ‘and she walked through that door, you’d be strangled and I’d be off to exile. You’re uncomfortable, aren’t you? You are almost sitting with your back to me, having to twist your neck round. Do you know who taught me that? Livia! She had a genius for making people feel uncomfortable: she taught me a lot more as well.’ She gently pushed me off the couch. ‘Kneel down.’

She sat on the edge of the couch, and I knelt on the floor before her. I could have refused, I was a free-born Roman citizen, but I was fascinated. I had never expected this to happen. Agrippina clasped her hands before her.

‘You are Parmenon,’ she began. ‘And you are related very slightly, may the Gods be thanked, to that human spider, that vile viper, the Prefect Aelius Sejanus. He’s a very, very dangerous man, Sejanus. Our Emperor’s dark shadow! A man of infinite ambition. You know he wants to be Emperor? Oh yes! He has pretensions enough. After all, if the line of Caesar can produce an emperor why not that of Sejanus?’

‘Yes, but-’ I protested.

‘But, but what?’ she mimicked. ‘Who’s in the way! Livia’s been dead two years. My father twelve!’

‘Your brothers?’

‘Drusus is in prison. He’s been lowered into a pit called the Sepulchre. Sejanus arranged that. They are going to starve him to death. And Mother? You are going to ask about my mother, aren’t you?’ she continued. ‘And my other brother Nero. Well, I’ll tell you where they are. Nero’s in Pontia and Mother’s on Pandateria, a little island. They say she’s gone mad, and they had to restrain her so forcibly she lost an eye. Can you imagine that, Parmenon? The kinswoman of Caesar Augustus, with her eye knocked out by a centurion, being force-fed by sweaty ex-gladiators, and roaming the rocks like a mountain goat?’

‘What about young Gaius?’ I replied.

‘Oh, you mean “Little Boots”. Well, he’s with the old fox in Capri. Only the Gods know what’s happening to him. Anyway!’ She moved a lock of hair away from her forehead. ‘I’ve told you enough. You can now trot back to Sejanus and report all the juicy bits.’ She clicked her fingers. ‘Go on!’

I remained kneeling.

‘Go on!’ she repeated.

‘If I do, you die!’

‘Aye, Parmenon, and so do you.’ She ruffled my hair with her fingers. ‘We are both trapped, aren’t we? You go and tell Sejanus’s minions what I have said and I’ll join my mother, or brother, on some lonely island.’ She pointed to the floor. ‘Or my other brother Drusus in the cells below. As for you, Parmenon, as time passes Sejanus will start to wonder. Why should young Agrippina open her heart to a stranger? Can this Parmenon be truly trusted?’

I strained my ears and hoped the gallery outside was empty. This remarkable young woman had trapped me.

‘Do you know why I chose to sit here, Parmenon? Because that door is thick and there are no ledges outside this window. I’ve also checked the walls and floor carefully. No spy-holes, no little apertures for the ear. So, what are you going to do, Parmenon? Choose life or death?’

‘I am. .’

‘What are you going to say, Parmenon?’ she mocked. ‘That you are only a servant, a scribe? You are only a flea on Sejanus’s table.’

‘Why are you doing this?’ I asked.

‘I don’t know. I am taking a gamble. I watched you at the amphitheatre. You don’t like bloodshed, Parmenon.’

‘I always think of my own skin.’

‘No, Parmenon, somewhere you’ve got a soul and a heart. I rather like you, you don’t act like an informer or a spy. So, let me draw you deeper into the net. We haven’t got much time. At the moment everybody’s drunk after the Games — nothing like a little blood is there, Parmenon, to whet the thirst and stir the cock — and Sejanus’s spies will be slaking themselves before they remember their duty. That’s their great mistake: blood blinds them. Such is Rome under Tiberius. Have you heard the poem, Parmenon?’ She closed her eyes.

‘“Tiberius is not thirsty for neat wine. What warms him up is a tastier cup, The blood of murdered men”.’

I shivered. Agrippina was muttering treason. Both of us could be handed over to the executioners to be strangled, our corpses tossed down the Steps of Mourning before being thrown into the Tiber.

‘He’s mad,’ Agrippina continued. ‘Tiberius is mad; either that, or possessed by a demon. Perhaps both. Do you know what my father told me, Parmenon? When Tiberius was a general, he used to study his maps in his tent the night before a battle, and suddenly the lamps around him would abruptly go out.’ She made me jump as she snapped her fingers. ‘Extinguished just like that! Tiberius always took it as a sign that his demon was nearby and he’d be lucky in the coming fight.’

‘Domina,’ I stammered. ‘You shouldn’t tell me all this.’

‘I’ll tell you more, Parmenon. Tiberius is the great Augustus’s successor but he spent most of his early manhood sulking in exile. It turned his mind. He wants to kill and kill again. My father is dead, my mother and two brothers will soon join him and, if Sejanus has his way, I and my sisters have got — ’ she coolly shrugged her shoulders ‘- perhaps a year, certainly no more than eighteen months. Go out and check the gallery again, Parmenon. Stay there for a while before coming back.’

I obeyed her command. I closed the door behind me and tried to stop trembling. Agrippina had sent me out to test me. Any sensible informant would have fled like the wind, certainly not to Sejanus but down to Ostia to beg, buy, do anything to gain passage to the western isles or beyond. My face was coated in sweat. My stomach was clenched so tightly I thought I was going to vomit. It was like being woken up from a deep sleep by a jug of cold water splashed over your face. I was no more than twenty-three years of age and so far my life had been like that of a dream-walker, an observer of what was happening around me, but feeling very little. My father killed, my mother a sickly woman who had died before her time. Friends and acquaintances were merely people I talked to, dined or slept with. In an hour all this had changed. I walked up and down the gallery drawing deep breaths. Why, I kept asking myself? Why was Agrippina telling me this? It was all true, of course. Tiberius was a sick, bitter man. The stories from Capri depicted him as a monster. One story currently doing the rounds of the taverns of Rome was that a fisherman on the island had caught an enormous mullet, and eager to please his Emperor, he towed the fish up the trackless cliffs and surprised Tiberius. The Emperor was furious at being disturbed. He ordered his guards to wash the fisherman’s face with the mullet; its scales skinned him raw and the poor fellow screamed in agony, ‘Thank the Gods I didn’t bring Caesar the huge crab I also caught.’

Tiberius sent for the crab, had it used in the same way, before his hapless victim was thrown from the cliff top. A party of marines stationed below dealt with the fisherman, as they did others sent hurtling to their death, whacking him with oars and boat hooks. The poor man’s corpse was left a bloody mess upon the rocks. In Rome the hunger for blood was no different. The prisons were full, and those detained were deprived of light, food, even conversation. Some of the accused, on being warned to appear in court, felt so sure the verdict would be guilty that, in order to avoid public disgrace, they stayed at home, took a warm bath and opened their veins. If Sejanus’s police suspected this might happen, the house was raided, the poor unfortunate’s wounds were bandaged and he was hurried off to prison. A few senators, knowing they were going to be accused in public, drank poison openly, toasting their colleagues whilst cursing Caesar’s name. Their corpses were always displayed on the Steps of Mourning, before being dragged by hooks along the muddy lanes of Rome to the Tiber. Men, women, even children were imprisoned. Sejanus often toured the prisons, where one of his victims, half-mad from the torture, begged to be put out of his misery.