Cato was momentarily shocked by his vehemence, and then he knew just how dangerous the Thracian was. He felt the hairs rise on the back of his neck as he stared at the man, and fear, ice-cold, spread through his guts. He swallowed and tried to speak as calmly as possible. ‘Why? Why do you hate them so much?’

Quertus stared at Cato from under his thick brows. ‘You don’t know?’

‘Why should I? If there’s a reason, then tell me.’

The Thracian lowered his head so that Cato could no longer clearly see his expression. ‘Roman, I know the Silures. I have lived amongst them. I was once their prisoner. They treated me worse than a dog. Bound me and tormented me with hunger and thirst, and beat me. Mocked me. Made fun of me . . . Humiliated me. Not just their warriors, but their women and children as well. You think children are innocent? Think again. Give them licence to do as they will and there is nothing they aren’t capable of. Nothing. Look.’ He rolled up his right sleeve and raised his arm. Cato saw that there was a crude lattice of white scar tissue. Quertus smiled grimly. ‘They did that with spear tips heated in the heart of a fire. On my arms, my legs, my back and chest. Children . . . They must die along with the rest. I will have it no other way.’

Cato felt some sympathy for the other man’s torment. Both Macro and Julia had once been prisoners of a rebel gladiator and his band of followers, and even though they had rarely spoken of it, he knew the experience had scarred them both. But experience does not justify behaviour, he firmly believed. There were no exceptions. He took half a step away from the Thracian and he responded gently, ‘I am giving you an order, Centurion Quertus. We will take prisoners.’

‘No!’ Quertus lowered himself into a crouch, like a cornered beast, and his sword hand grasped the handle of his weapon. ‘They die! And I will kill any man who shows them mercy.’

‘Then you’ll have to kill me.’ Cato spoke without thinking and was horrified by his foolishness. His fingers crept up his thigh towards his sword.

‘Kill you?’ Quertus chuckled. ‘Do you think I couldn’t?’

Cato’s heart was beating like a hammer inside his chest. ‘I wouldn’t be the first Roman you have killed, right?’

‘Not by a long way, Prefect.’ There was a faint scrape as he began to draw his blade.

Cato reached for his weapon but resisted the temptation to rip it from the scabbard. ‘That’s enough, Quertus. Think about what you’re doing. You threaten me with a weapon and, by the gods, I swear I’ll have you crucified.’