‘Because they pose no risk to me at present. If they did, then I would do as you say. But for now I am content to have Festus watch them. If they attempt anything we shall catch them, and then I will have proof of Crassus’s treachery. Enough to give me a little power over him, since I doubt the Senate would look too kindly on any man conspiring to murder a proconsul.’ Caesar smiled wryly. ‘In any case, I am not yet convinced that is his plan. I think Crassus has simply sent the man to spy on me, report back, and make a small fortune for his master in the process. Now that would be typical of Crassus!’

Marcus was not so sure. ‘If you say so, sir.’

Caesar’s expression became serious again. ‘There’s one thing that might complicate matters, and that’s if Decimus recognizes you. He must already know that you are a member of my household, since that agent of his attempted to poison me.’

‘Thermon.’

Caesar nodded. ‘So far Decimus has not seen you here and let’s hope he assumes that you are still in Rome. If he does find out, then he will know he’s in danger.’

‘Danger, sir?’

‘Of course. You are the only witness to his murder of your father and the kidnapping of you and your mother. If he is ever prosecuted for that crime, then he would face exile or execution. Which means that it would be dangerous for you if he knew you were here. Bear that in mind and stay clear of the man, and his followers. That’s an order.’

‘Yes, sir.’

Caesar looked at Marcus shrewdly. ‘I know you are a freed man now, but you are part of my army in this campaign and that makes you subject to military discipline. An order from your general is just as binding as an order from your master. Is that clear?’

‘Yes, sir. Perfectly.’

Caesar nodded with satisfaction. ‘Good. Now I need a little time to think about the campaign.’ He waved his hand back towards the staff officers riding a short distance behind. Marcus bowed his head and reined in to allow the proconsul to draw ahead. But he could not heed his warning. Much as he respected Caesar, Marcus had his own ambitions, which he placed above his duty to obey a superior.