Cato rose stiffly and picked up his helmet. As he tied the straps he strode over to Macro and prodded him in the side with the tip of his boot.

Macro groaned and recoiled with a smack of his lips and a sleepy, ‘Arrrrr.’ Then his eyes opened and he sat up, rubbing his thick curls vigorously. ‘What’s up?’

‘Seems the enemy are on the move.’

‘Right,’ Macro muttered decisively. He picked up his helmet and stood up. ‘Let’s have a look then.’

Up on the platform the section commanded by the optio was staring down the slope. The optio indicated a tall figure in the corner. ‘That man, sir.’

A light drizzle was falling, just enough to impart the faintest of hisses as it fell on the timbers and turf of the fort. There was no sign of any stars, just a barely discernible mass of dark cloud weighing down the sky. The two officers approached the sentry quietly and took up position at his side.

‘All right, lad,’ Macro said softly. ‘What’s happening?’

The legionary replied without looking round. ‘I heard a clatter a moment back. Like a spearshaft catching on the trim of a shield, sir.’

‘That’s a pretty precise description. You sure about it?’

‘I’ve heard the sound enough to know, sir. I’m sure.’

‘All right.’ Macro nodded, then leaned forward to peer into the gloom alongside Cato. For a moment both men were still, then Macro eased himself back and shook his head. ‘Whatever it was, there’s nothing there now.’

Cato did not move. Even as he was listening his tired mind would not rest. He calculated that there was no more than an hour left before dawn. The light would begin to return to the world long before then. It was the best time to attack. The defenders of the fort were sure to have had a sleepless night for the most part. They would be weary and on edge so that the slightest thing would further shake their nerves and undermine morale.

‘I said, there’s nothing there,’ Macro repeated patiently.

Cato turned towards him with an irritable expression. ‘I heard you, Centurion. And I’ll be obliged if you kept your opinions to yourself until I ask for them.’

Macro breathed in deeply and bowed his head. ‘As you command, sir.’

‘That’s right.’ Cato took one last look down the slope to satisfy himself that the fort was safe for the moment. Then he turned back to Macro. ‘I want Maridius up here on the tower at first light so I can show him to Caratacus. Have him chained in one of the nearest stables so we can get him quickly, if need be.’

‘Yes, sir.’