Marcus thought for a moment. ‘I pray that they will see reason, sir. If you guarantee their lives, then I think they would prefer to live than face death by the sword, or on the cross.’

‘The ringleaders will have to be executed, of course.’

‘No. They will be spared too.’

Caesar shook his head. ‘That would not play well in Rome. The Senate and people will demand the deaths of Brixus and his companions.’

‘You are the commander here, sir. It is your decision, not theirs.’

Caesar leaned back in his chair and drummed the fingers of his right hand on the desk. ‘What is to stop me ordering Festus to take you aside and beat the truth out of you? He has a certain skill for loosening tongues.’

Marcus fought to keep the fear from his expression. ‘You could torture me, sir. But I might endure it for some hours, by which time Brixus and his rebels would have escaped. I know that time is precious to you. The campaign must be finished before you can march against Gaul. This is your chance to put an end to it today. Otherwise it could drag on for months.’

Festus coughed. ‘The boy has a point, sir.’

‘Quiet!’ Caesar snapped. ‘If I ever want your opinion, I’ll ask for it.’

‘Yes, sir. Sorry, sir.’

Caesar ignored his bodyguard and kept his attention on the boy sitting before him. Marcus stared back unwaveringly, but inside he was terrified. He felt small and alone in the presence of great danger, yet he knew that he had one powerful weapon on his side: time. Every passing moment increased the risk that Brixus and his followers would slip through Caesar’s fingers. That was what he was counting on. If he had misjudged his former master, then Marcus was certain that he would be dead by the end of the day, and would be swiftly followed by thousands of others before the rebellion was over.

‘Very well,’ Caesar growled through clenched teeth. ‘You have a deal.’

‘I want your word on it.’ Marcus swallowed. ‘I want you to swear to it, here in front of Festus.’

‘And what oath would you bind me to?’ Caesar asked mockingly.

‘One that I know you will keep. I want you to swear on the life of your niece, Portia.’

The blood drained from Caesar’s face and Marcus feared that he had pushed the proconsul too far. Then Caesar nodded slowly.

‘I swear, on the life of my niece, that I will not harm those rebels who choose to surrender.’

Marcus felt a wave of relief sweep through his heart and was about to offer his gratitude when Caesar held up his hand to still the boy’s tongue.