There was a dull rumble before a great rolling crash that seemed to go on and on. Hadrian sniffed the air. ‘Strange, did not see any sign of a storm.’ There was silence, no sound of rain on the tent stretched over their heads nor any more thunder. Outside, men began to shout and cheer.

‘We may have our luck,’ Crispinus said. Princess Azátē appeared, heavily veiled and in her finery to meet the acting governor. ‘Apologies, lady, but we must go.’ Hadrian stood, gave the slightest inclination of the head, for no more was appropriate, treated her to an encouraging smile and dashed outside with the legatus. Ahead of them, hovering over the city was a great cloud, almost a fog, thicker and paler than the smoke from the fires. Soldiers were lining the camp rampart, staring at it and talking excitedly.

Hadrian grinned at Crispinus. ‘Let’s take a closer look!’

There was no point climbing the observation tower, so they pressed on, into the redoubts and other works left after the fire. They found the primus pilus dancing, an odd, ungainly sight, and Crispinus could not remember ever seeing the man so excited or so cheerful. ‘Got you, you bastards! Got you! Thought you’d won, didn’t you? Yes, you did! Stupid bastards. Now look what you’ve done! Ha! Serves you right, you little buggers!’

‘I take it there is good news,’ Crispinus said, as suavely as he could. The primus pilus calmed a little, and stopped shouting, contenting himself with waving his fist at the city – or at least where the city should be through the thick cloud of dust. They were all coughing.

‘We’ve a breach,’ Caecilius shouted, and grabbing Rufus by the arms, whirled him around. ‘A breach!’ He let the young centurion go and started screaming at the city again. ‘Didn’t expect that, did you, you little sods!’

‘The wall is down, sir,’ Rufus explained. ‘Part of the tower as well. They must have undermined them with their own tunnel. Maybe more collapsed than they expected or they just didn’t think it through.’

‘Not sensible then, like us,’ Hadrian said, wooden faced, but the irony was weakened when he started to cough.

*

Slowly, the dust cloud thinned and cleared, although the air seemed so unnaturally still that it took hours. Thirty feet of curtain wall had collapsed altogether, and the corner tower was leaning outwards, a great crack running down from the top. A lot of spoil had dropped forward, piling around the remnants of the Roman ramp.

‘Can we get up there?’ Crispinus asked his consilium, once the officers had been summoned. Hadrian was present, but had begun by saying that he was not there to take over from such an able legatus. He was there to help as best he could.

‘Not yet,’ Caecilius said. It was hard now to remember his earlier enthusiasm.

‘If we work all night, should be able to ready by noon tomorrow,’ Rufus explained. ‘We need to make a new ramp strong enough to take the weight of the attacking column. And get some ladders to help climb wherever there is still a slope.’