The whirring peaked and then suddenly the air was filled with a thwipping noise an instant before the shot struck home with a series of sharp cracks all along the palisade. With a loud ringing one clattered against Cato’s shield boss, knocking it in so that as Cato loosened his grip he felt the dented metal brush against the back of his knuckles. A lucky shot, Cato smiled ruefully, and of course it had to strike his shield. An instant later one of the slingers was even more lucky. A heavy round stone passed clear through a gap in the crude palisade and smashed into the ankle of a legionary just to one side of Cato. The man cried out as his bones were pulverised by the impact and he crumpled to one side, clutching at his ankle, and starting to howl in agony.

Cato turned towards his optio. ‘Septimus! Get him off the rampart!’

Under the cover of his shield the optio clambered over to the injured man, grabbed him by the forearm and dragged him bodily down the rear of the rampart to where the rest of the injured lay along the base of the defences. No one could be spared to attend to their wounds while the cohort was under attack, and they lay in the afternoon sun, some crying out, but most of them still, biting back on their pain. Those who could, saw to their own injuries and then tried to help the men around them. Septimus hauled his casualty over to the end of the row of injured and then scurried back into position on the palisade.

As the rattling fusillade continued, more shots found their targets and took a slow steady toll of dead and wounded, even as they continued to batter and splinter the broad shields that lined the top of the rampart. Time was on the Romans’ side, Cato comforted himself as he hunched down and gritted his teeth as another slingshot cracked against the surface of his shield. The longer Caratacus kept this up, the closer Vespasian came to closing the trap. But there was no sense in the Third Cohort exposing themselves to more damage than necessary.

‘Stay down!’ Cato called to his men as he dropped back out of line and scrambled along the rampart to where Tullius sheltered behind his shield.

‘Sir!’ Cato called. Tullius glanced round.

‘Sir, shouldn’t we pull the men back on to the reverse slope, out of the line of fire?’

Tullius shook his head. ‘They can take it. Besides, we don’t want the enemy thinking we’ll duck a fight.’

‘This isn’t a fight, sir.’ Cato waved his hand to the growing line of casualties below the rampart. ‘It’s just a waste of good men.’

‘I’ll be the judge of that, Centurion!’ Tullius snapped at him. ‘Now return to your position.’