‘I believe that we are surrounded by mystery. There’s room for anything in mystery, even the gods.’

‘Hippocrates said that this illness would only be called the “sacred disease” until its causes were discovered.’

‘Hippocrates was right but, unfortunately, the disease continues to be “sacred” today and will remain so, I fear, for some time to come. And yet I cannot afford to give any public display of my weaknesses. You can understand that, can’t you?’

‘I can. But the only one who can tell when an attack is coming on is you. They say that the sacred disease gives no warning, but that each man reacts differently to it. Have you ever had a sign, something that made you think an attack was about to take place?’

Caesar drew a long breath and remained silent, forcing himself to remember. At length, he replied, ‘Perhaps. Not any clear sign, nothing that is identical from one time to the next. But occasionally it happens that I see images from other times, suddenly. . like flashes.’

‘What kind of images?’

‘Massacres, fields strewn with dead bodies, clouds galloping, shrieking like Furies from hell.’

‘They might be actual memories, or simply nightmares. We all have them. You more than anyone, I imagine. No one else has lived a life like yours.’

‘No, they’re not nightmares. When I say “images”, I’m talking about something I actually see in front of me, like I am seeing you now.’

‘And are these. . visions always followed by attacks of this sort?’

‘Sometimes they are and sometimes they aren’t. I can’t say for certain that they are connected to my disease. It’s a sly enemy I’ve made for myself, Antistius, an enemy with no face, who pounces, strikes and slips away like a ghost. I am the most powerful man in the world and yet I’m as helpless in the face of this as the lowest of wretches.’

Antistius sighed. ‘If you were anyone else, I would recommend. .’

‘What?’

‘That you withdraw into private life. Leave the city, public office, political strife. Others have done so before you: Scipio Africanus, Sulla. Perhaps the disease would let go of you if you let go of your daily battles. But I don’t suppose you’d ever follow my advice, would you?’

Caesar raised himself into a sitting position on the side of the bed, then swung his feet to the floor and stood up.

‘No. I can’t afford to. There are still too many things I must do. I’ll live with the risk.’

‘Then surround yourself with men you trust. Arrange things so that, if it should happen, someone is there to cover you with a toga and there is a closed litter ready to take you where no one can see you. I will be waiting there for you. When the crisis has passed you will be able to return to what you were doing as if nothing had happened. That’s all I can say.’

Caesar nodded. ‘It’s good advice. You can go now, Antistius. I feel better.’

‘I’d rather stay.’

‘No. You must have other business to attend to. Send in Silius with my breakfast. I’ll have something to eat.’

Antistius nodded. ‘As you wish. Along with your breakfast, Silius will bring you a potion I’ll mix for you now. It will help to thin the humours of your spleen. That should provide some relief. Now, lie back and give those stiff limbs a little rest. When you feel stronger, a hot bath and a massage would be in order.’ There was no answer from Caesar and Antistius walked out with a sigh.

He found Calpurnia in the atrium, sitting in an armchair. She was still wearing her nightgown and she had not bathed or eaten. The signs of strain were evident on her face and in her posture. When she saw Antistius heading for the kitchen, she followed him.

‘Well?’ she asked. ‘What do you think?’

‘There’s nothing new, but unfortunately I have the impression that the disease has taken hold. For the moment all we can do is seek to limit its effects. However, we can always hope that it will go away as suddenly as it started. Remember that Caesar is a man of great resources.’

‘No man can weather so many storms of the body and spirit without suffering lasting damage. The past ten years have been as intense as ten lives and they’ve taken their toll. Caesar is fifty-six years old, Antistius, and yet he intends to embark on another expedition in the East. Against the Parthians.’

As the doctor was crushing seeds in a mortar and then setting them to boil on the stove, Calpurnia sat down. A maidservant began preparing her usual breakfast, an egg cooked under the embers and some toasted bread.

‘And that woman is only making the situation worse.’

Antistius didn’t need to ask to whom she was referring. Cleopatra VII, the Queen of Egypt, was living in Caesar’s villa on the far side of the Tiber. He fell silent, knowing what would happen if he expressed any opinion at all on the subject. Cleopatra had even brought her child to the villa with her, a boy she’d dared to call Ptolemy Caesar.

‘That whore,’ Calpurnia continued, realizing that Antistius was not going to pick up on her invitation to join the conversation. ‘I hope she drops dead. I’ve even had the evil eye put on her, but who knows what antidotes she’s found to protect herself, and what philtres she’s given my husband to drink to keep him bound to her.’

Antistius couldn’t help but speak. ‘My lady, any middle-aged man would be flattered to conceive a child with a beautiful woman in the bloom of youth. It makes him feel young, vigorous. .’

Here his voice dropped off and he bit his tongue: not exactly the most diplomatic of things to tell a woman who had never been able to have children herself.

‘Forgive me,’ he added hastily. ‘This is really no affair of mine. What’s more, Caesar doesn’t need to feel vigorous. He is vigorous. I’ve been a doctor my whole life and I’ve yet to see another man of such a hardy constitution.’

‘Never mind. I’m used to hearing such things,’ replied Calpurnia. ‘What worries me is the enormous burden he is carrying. He can’t keep this up much longer and I’m sure there are many men out there who would like nothing better than to see him on his knees. Many of those who feign friendship today would turn into bloodthirsty beasts tomorrow. I trust no one, you understand? Nobody.’

‘Yes, my lady, I do,’ replied the doctor.

He took his potion off the flame, filtered it and poured it into a cup that he set on the tray where the cook was arranging Caesar’s breakfast: fava beans, cheese and flatbread with olive oil.

Silius entered and took only the potion.

‘Does he not want breakfast now?’ asked Calpurnia.

‘No. I’ve just spoken to him and he’s changed his mind. He no longer wants to eat. He’s gone out on to the terrace.’

‘Your potion, Caesar.’

Caesar had his back to Silius, his hands on the balustrade. He was facing the Aventine Hill, from where a flock of starlings had risen like a dark cloud flying towards the Tiber.

He turned slowly, as if he’d only just realized that Silius was present. He took the steaming potion and set it on the parapet. After a few moments he lifted it to his lips and took a sip.

‘Where is Publius Sextius?’ he asked after he’d swallowed.

‘Centurion Publius Sextius is in Modena, on your orders, Caesar.’

‘Yes, yes, I know that, but according to my calculations he should be heading back by now. Has he sent a message?’

‘No, not that I know of.’

‘If a letter arrives from him, inform me immediately, at any time of day or night and no matter what I am doing.’

‘You’re expected shortly at the Temple of Jupiter Optimus Maximus at the Capitol to offer a sacrifice. If you’re feeling strong enough, of course.’

Caesar took another sip of the potion and looked Silius in the eye.

‘Of course. At times I forget I’m the High Priest of Rome and yet it should be my foremost concern. . No bath and no massage, then.’