‘That’s not possible, sir. The food we can restrict, but they can’t do without water. Not if we want them in a fit state to ride.’

‘What do you suggest?’

Quertus gestured towards the rear of the fort. ‘There’s a narrow track that winds down the cliff there. Wide enough for a man to lead a horse. My lads can take ’em down there to the river to be watered.’

Cato considered the suggestion. ‘Best do it under cover of darkness.’

‘Too dangerous, sir. If they put a foot wrong on the path they’ll fall into the river. We can only use the path in daylight.’

Cato sighed in exasperation. ‘Then see to it. Make sure you give the handlers an escort in case the Silurians try to spring a trap.’

He considered the exchange concluded, but Quertus did not move away.

‘Is there something else, Centurion?’

‘Just the question of what you intend to do next . . . sir.’

‘Do?’

‘I’m next in the chain of command. If you fall, then I will need to carry out your intentions.’

Cato smiled thinly. ‘I intend to defend the fort.’

Quertus nodded in the direction of the enemy camp, his earlier bluster gone. ‘We’ve beaten them off once, but we can’t do it indefinitely. If we lose men at the rate we did earlier then it’s only a question of a few more attacks before we’re spread so thinly they’ll overwhelm us.’

‘I thank you for that assessment,’ Cato responded curtly.

‘We can’t stay trapped in here. We have to get out.’

‘That’s not possible. We’re surrounded, in case you hadn’t noticed.’

‘Then we’ll have to break out. While we still have enough men to do it.’ Quertus glanced up. ‘If this weather holds, it’ll be dark tonight. Dark enough to cover our escape.’

‘And dark enough to have us blundering into each other, if not the enemy.’

‘What if we use our prisoners as a shield? Caratacus would hardly let his men attack us if there was any danger to his brother and the others.’

Cato shook his head. ‘He might not. But given the suffering you’ve visited on the local people in recent months, I dare say Caratacus will have trouble restraining his allies. They want nothing more than to butcher us all and take our heads as trophies. It’s too dangerous. We’ve been over this, Quertus. Our best chance is to sit it out until we are relieved. That’s my decision.’

The Thracian gave him a frosty look. ‘It’s the wrong decision.’ Before Cato could respond, he turned and strode away, back towards his men resting on the slope leading up to the wall.

Macro glared after him. ‘The enemy would be doing us a favour if they knocked that gobshite on the head.’