‘Onagers?’ Macro looked astonished. ‘Where the hell would Bannus have got onagers?’ Even as he spoke, a memory flashed through his mind. Weeks earlier, when the caravan had rejected Postumus’s offer of protection. In amongst the camels had been two covered ox-carts, carrying heavy timbers. No doubt the iron ratchets and other mechanisms had been hidden beneath the load. Very clever of the Parthians, Macro conceded. Rather than send the siege weapons across the desert, they had shipped them round Arabia and then smuggled them to Bannus under the guise of caravan goods. Macro bunched his hands into fists and thumped them down on the rampart.’I saw those a while back, broken down for transport. On that first patrol with Postumus. Of course, I was too foolish to recognise the components for what they were. Shit.’

Cato shook his head. ‘Well, it’s too late to do anything about it now.’

Macro was about to reply when they both heard a sharp shout from the enemy camp. They turned just in time to see the throwing arms of the onagers slash up and forwards until they struck the padded cross pieces. The dull thud of that impact sounded an instant later. Cato saw the first two boulders hurled up through the cold morning air. They rose to the top of the arc that defined their trajectory, seemed to hang there for a moment, and then came down at an alarming speed, rapidly gaining in size as they plunged towards the gatehouse.

Cato grabbed Macro and hauled him away from the rampart. ‘Get down!’

07 The Eagle In the Sand

CHAPTER TWENTY-FIVE

They hunched down and waited for the impact with gritted teeth. The first rock overshot the gatehouse and smashed through the roof of the barracks block beyond with a shattering crash. Fragments of tiles exploded from the impact and pattered down on to the street around the building. The second missile struck the ground a short distance before the fort sending a shower of stones and grit against the wall, and raising a small cloud of dust above the spot where it had landed. Cato and Macro felt the impact and Macro looked at his friend with a nervous grin.

‘That’s quite some piece of kit they have there. Good range, and it can throw a decent weight. That’s going to be a nuisance.’

Cato stood up and stared towards the onagers. Already the crews were working at preparing them for the next blow. He heard a thin series of clanks as the throwing arm was ratcheted back. Macro had hurried to the other side of the gatehouse and was staring down at the barracks block that had taken the first strike. There was a gaping hole in the roof and a haze of dust hanging over the building.

‘Hey, you!’ Macro yelled down to one of the soldiers in the street.The man looked round and up and stood to attention.

‘Yes, sir!’