‘It will have to,’ Cato replied softly. ‘When they finish off what’s left of the gatehouse, that’s all there is to keep them out.’

By the wavering glow of the torch he held in his hand Macro turned to stare at his friend. ‘You’re right, of course. They will finish the job in the morning.’

‘Unless something is done about those onagers tonight.’

‘I told you,’ Macro responded wearily. ‘It’s too dangerous.’

‘We’re in danger either way,’ said Cato. ‘At least if we try something we might be able to set them back a day or so and buy ourselves some time. It has to be worth trying, sir.’

Macro wasn’t convinced. ‘I told you, whoever goes out there under cover of darkness is bound to lose their way through the defences.’

Cato was looking at Macro’s torch and Macro noticed the excited glint in his friend’s eyes that always accompanied the sudden rush of thought when Cato came up with one of his hare-brained schemes. He felt his heart sink.

‘Let me lead a raid, sir.’

‘Are you so tired of living already, Cato?’

‘No, I’m just not terribly keen on sitting here, waiting to be killed. Besides, I think there’s a way of safely passing through our defence lines . . .’

‘Are you sure about this?’ Macro said softly as he looked at Cato.The young centurion had blackened his face and the rest of the flesh that was not covered by the dark brown tunic that he wore. His sword belt was buckled round his waist and a haversack hung from his shoulder containing a tinderbox and several small pots of oil. Behind him stood a party of twenty men, similarly equipped for the night’s work.

‘I’ll be fine, sir. Just make sure those lamps are kept alight.’ Cato nodded up to the rampart where the wan glow of an oil lamp flickered in the darkness. Back at headquarters a second lamp had been lit and placed in the highest window in line with the lamp on the wall and the narrow path through the screen of traps and obstacles that stretched out beyond the north wall of the fort.

Macro clasped his friend’s arm. ‘Do what you have to do and come straight back. Don’t get carried away. I know what you’re like.’

Cato grinned. ‘Trust me, sir. I don’t want to be out there any longer than I have to.’

Macro gave Cato’s arm a brief squeeze. ‘Good luck then.’