Septimus gave a contemptuous snort.’They’re wasting their time. There’s nowhere they can deploy here. They’ll have to fight us on a narrow front. It’s going to hurt them more than it’s going to hurt us.’

Cato smiled faintly as he turned to look down the track. There was no point in reminding the optio that even a few thousand Britons might have an outside chance of besting a handful of legionaries. He turned back to the lookout.

‘I want you to run back to Centurion Tullius. My compliments to him, and tell him the enemy is in sight. We’ll fall back slowly and delay Caratacus for as long as we can. Got that?’

The legionary nodded. Cato raised a hand to shade his eyes as he stared down the track. ‘Where’s the other lookout?’

The legionary turned to follow the centurion’s gaze. ‘Decimus was trying to estimate their strength before he followed on. Here he comes, sir.’

A distant figure came scurrying round the bend, head down and heavy shield bobbing as he ran. His comrades began to shout encouragement as Decimus sprinted for all he was worth. Every so often his helmet glinted as he turned to glance back. The first of the enemy horsemen appeared round the bend when Decimus was still a hundred and fifty paces from the rest of the century. Cato cupped a hand to his mouth, shouting alongside the rest of his men as the optio looked on with a frown. Cato guessed that a veteran like Septimus thoroughly disapproved of officers who refused to comport themselves with a cool detachment. Sod him, thought Cato. There was a time and a place for a stiff and unyielding demeanour, and this was not it.

‘Run, man! Run! The bastards are right on you!’

Decimus threw down his javelin, but kept hold of his shield and staggered on. Behind him the enemy warriors, more than thirty of them, urged their mounts forward, determined to ride the Roman down before he could reach the safety of the tight line of red shields that stretched across the track. The tips of their spears glittered as they dipped and were lined up on the back of the man fleeing from them.

‘He’s not going to make it,’ Septimus decided. ‘They’ll have him.’

‘No,’ Cato replied instantly. ‘Come on, Decimus! Run!’

There was not much further for the legionary to cover, but there was even less between him and his pursuers.

‘I told you . . .’ There was no mistaking the trace of smugness in the optio’s voice, and Cato burned with cold fury at the man’s callousness. The horsemen would not have Decimus if there was anything he could do about it. The centurion turned away from the desperate spectacle, towards the rest of his men.

‘Front rank! Ready javelins!’