‘He might. If he can spare the men. Don’t forget, there’s that force of Parthians moving up on Palmyra.’

‘I’m sure he can spare us some men. Enough to deal with Bannus before his army grows much more.We’ll stay here until the relief arrives.’

‘Stay here?’ Cato looked uncertain. ‘Is that wise?’

‘What else can we do? We’ll be safe enough in here.’

‘You think so?’

‘Why not? He’s got a force of brigands, and now, it seems, a few Parthians. They’re not going to get over the walls in a hurry. Not without siege weapons.’

‘What makes you think they lack those?’

Macro smiled. ‘And where would they have spirited them up from?’

‘Parthia, that’s where.’

‘Cato, have you any idea how difficult it would be to move a siege train over the desert?’

‘No. How difficult?’

Macro was taken aback, and struggled for an answer. ‘I don’t really know, but I should imagine it would be bloody difficult to haul anything across the terrain out there. All right?’ He gestured vaguely in the direction of the caravan trade route and the desert beyond.’I'm telling you, he has no siege weapons. We’re safe.’

‘I hope you’re right.’

‘I’m right. But we’re going to make some preparations all the same.’ Macro made a few mental calculations. ‘Heshbon, that’s what, thirty miles away. They should be here tomorrow then, from noon.’

Cato nodded. ‘Sounds right.’

‘Then there’s not much time.We need to speak to the Governor. Come on.’

They climbed back into the tower. Longinus and Postumus were watching the rapidly diminishing cloud of dust kicked up by the Parthian horses and discussing something in muted tones. They stopped as soon as Macro and Cato emerged from the trapdoor. Macro quickly described what the patrol had seen. There was a momentary look of alarm on the Governor’s face before he controlled his feelings again and stood, stroking his chin thoughtfully.

‘I’ll have to re-join my command before the fort’s cut off.’

‘Yes, sir,’ agreed Macro. ‘The sooner you leave, the better. We’ll wait here for the relief column.’

‘Relief column?’ Longinus repeated. ‘Yes. Yes, of course. I’ll have to send you some more men. Enough to beat Bannus. I’ll see to it the moment I return to my command.’

‘Very good, sir.’ Macro nodded.

‘I’d best leave at once then.’ Longinus turned towards the trapdoor. Then he paused and turned back, staring hard at Postumus. ‘You can stay here.’

‘What?’ Postumus looked horrified. ‘Stay? Sorry, sir, but my place is at your side. It’s going to be a dangerous journey back to the legions. You’ll need every man you can get to ensure your safety.’