Cato shook his head wearily. ‘All those men lost, and we only managed to destroy one weapon.’

‘One destroyed. One damaged.That’s a good result by any measure, Cato. You’ve halved the weight of their bombardment and set them back a while until the repairs are complete. You and the others did as much as could reasonably be expected. So don’t go and put yourself down, and don’t rubbish the effort of those men who didn’t make it back last night,’ Macro said frostily. ‘In the circumstances we had to try something, or just sit here and wait for them to come to us. We did the right thing.’

‘Maybe, but if it just postpones the inevitable, then that’s small comfort. I wonder if the men who . . .’ Cato’s voice faded as his gaze was drawn to a group of men working close to the burned onager. They had been busy cutting away the salvageable timber and constructing something on the ground next to the remains of the siege weapon. Now several small parties of the enemy were distributing lengths of jointed wood, fashioned in some kind of crosspiece. He pointed them out to Macro.

‘What are they up to?’

The older officer strained his eyes for a moment and shook his head. ‘Beats me. Framework for a ram housing, maybe.’

As they watched there was a brief commotion in the enemy camp and then a crowd of men marched towards the siege engines. As they got closer Cato could see that they were jostling a small party of captives with dark tunics and smeared skin. He felt a sinking feeling in his guts as he recognised one of the prisoners.

‘I think that’s Sycorax . . .’

Even as he watched them approach the hastily arranged constructions lying on the ground Cato could guess what was coming next, and he felt his stomach clench and feared he was going to be sick. The prisoners were split up, one man being dragged to each crosspiece. The tunics were torn from their bodies and then they were held down against the wood while heavy iron nails were driven through their wrists and ankles. The sound of the hammer blows rang out over the open ground, accompanied by terrified screams of agony from the Roman prisoners.