At the first hint of the sky lightening Vespasian gave the order for the First Cohort to move up to their start line and make ready to advance. Small teams of engineers, carrying ladders and a battering ram, accompanied them. One century had been issued with composite bows to provide close fire support when the cohort was ready to force the main gate. All of them stood ready, dim ranks of silent men, heavily armoured, weapons sharpened and hearts filled with all the usual tensions and misgivings about such a dangerous assault. Fighting a setpiece battle was nothing compared to this, and even the rawest recruit among them knew it.

From the moment the bolt-throwers ceased firing on the palisade, the First Cohort would fall under a rain of arrows, slingshot and boulders. Due to the twists and turns in the approach ramps, one or other of their flanks would be exposed to enemy fire before they even reached the main entrance. Then they would have to endure more of the same while they attempted to breach the gate. Only then would they be able to close with the enemy. It was only natural that the men who had endured so much punishment would want to exact bloody retribution once the Durotriges were within swords' length. Vespasian had therefore personally briefed each officer in the cohort to look out for Cato and his party and that every effort must be made to take prisoners. He told them he needed live slaves if he was ever going to be able to afford to renovate his house on the Quirinal Hill, back in Rome. They had laughed at that, as he'd known they would, and Vespasian hoped it would be enough to prevent Cato and his men being slaughtered out of hand when the legionaries eventually burst onto the plateau.

'All ready, sir,' Tribune Plinius reported.

'Very well.' Vespasian saluted and looked over his shoulder.

The horizon away to the east was becoming noticeably lighter. He turned back and regarded the looming immenseness of the hill fort. The wicker man towered above the palisade, the auburn twists of cane and branch slowly becoming visible as dawn strengthened and banished the monochrome shades of the night. The crews on the artillery platform stood still, watching the legate, waiting for the order to open fire. Vespasian had managed to muster over a hundred serviceable bolt-throwers, and each one now sat ready for winding back the torsion arms. The iron-headed bolts were already set in each channel, their dark-flanged heads pointing up at the defences surrounding the main gate. The first rays of the sun caught the shining bronze helmets of the Durotriges lining the palisade, watched by the legionaries in the cool gloom below. Gradually the glow flowed down the slopes of the ramparts.

Vespasian nodded to Plinius.

'Artillery!' Plinius roared through cupped hands. 'Make ready!'

The dawn air was filled with the sound of clanking levers and straining men as the torsion arms were wound back and the bolt ropes locked down against the projectiles. As the last crew finished, the sound died away and a peculiar stillness fell over the scene.

'Open fire!' Plinius shouted.

The crew captains pushed the release levers forward and Vespasian's ears resounded to the sharp crack as the torsion arms sprang back. A thin veil of dark lines streaked up towards the palisade. As was always the case, a number fell short and buried themselves in the slopes. Others overshot and disappeared way beyond the palisade – where they could still be a hazard. The crews would mark the fall of their shots and adjust the elevation accordingly. The vast majority, however, struck home in the first volley. Vespasian had seen the impact of such firepower a few times before, but even he marvelled at the destruction it caused. Whole timbers in the palisade were shattered by the heavy iron-headed bolts, splintered fragments whirling into the air, and the palisade soon had the appearance of a mouth filled with bad teeth.

The second volley was more ragged than the first as the more efficient crews fired earlier, and soon the disparity in loading times led to an almost continuous crashing from the released torsion arms. The palisade was brutally beaten down, and most Durotrigan warriors foolhardy enough to mount the rampart behind and shout their defiance paid the price. Vespasian idly watched as one big man waved a spear, until a bolt caught him high in the chest and simply whipped him bodily out of sight. Another was struck in the face, the blow completely shearing off the man's head. His torso remained upright for a moment, then collapsed.

Less than an hour later the defences about the main gate were in utter ruin, the stakes that had made up the palisade reduced to stumps, streaked with crimson. Vespasian motioned to his senior tribune. 'Send the cohort in, Plinius.'

The tribune turned to the trumpeter and ordered him to sound the advance. The man put his lips to the mouthpiece and blew a sharp series of rising notes. As the first call echoed back from the ramparts, the centurions of the First Cohort gave the order to advance, and in two broad columns they began marching towards the approach ramps. The sun was low in the sky, and the backs of the men's helmets threw back a thousand reflections into the eyes of their comrades watching the fight from the legion's fortified camp. A substantial reserve of men stood ready to reinforce the First Cohort should it be roughly handled by the Durotriges. More men had been sent out during the night to position themselves round the fort and stand off, ready to intercept any enemy attempting to flee the far side of the fortress should the gate fall. Nothing had been left to chance.

The First Cohort, accompanied by their engineer detachment, mounted the first approach ramp and immediately had to turn parallel to the hill fort as they climbed at an angle towards the first dogleg. Already, some of the braver souls among the defenders were popping up along the ruin of their palisade and loosing arrows or slingshot into the massed mailed ranks of the legionaries, and Roman casualties began to fall out of line. Most were wounded and tried to cover themselves with their big shields while they waited to be carried to the casualty stations. Some were killed outright and lay still, sprawled on the track leading up the ramp.

Over the heads of the First Cohort the barrage of iron bolts continued to sweep the defences clear, but soon the crews would begin to imperil their own men. Vespasian held off giving the order to cease fire, willing to risk a shot falling short rather than permit the enemy to swarm over the remains of their defences and pour down a far more damaging rain of missiles on the heads of the legionaries.

The cohort reached the first dogleg and turned the corner, doubling back on itself as it climbed towards the main gate. The bolts were whirring less than fifty feet above their heads now, and the staff officers around Vespasian were getting edgy.

'Just a little longer,' the legate muttered.

There was a splintering noise from the artillery platform, and Vespasian swung round. The arm on one of the bolt-throwers had snapped under the strain. A loud chorus of groans came from the staff officers. Up on the second rampart the bolt from the broken machine had fallen short and skewered a file of legionaries, hurling them into an untidy bundle at the side of the track. The succeeding ranks of legionaries faltered for a moment, until an angry centurion laid into them with his vine cane, and the advance continued.

'Cease fire! 'Vespasian shouted over to the artillery crews. 'CEASEFIRE!'

The last few bolts cleared the heads of the First Cohort, thankfully, and then there was an eerie quiet, before the defenders realised the danger was gone. With a roar of their battle cry they ran out from cover and swarmed onto what remained of their defences above and around the main gate. At once a hail of arrows, stones and rocks pelted down on the men of the First Cohort. The commander of the cohort, the most senior and experienced centurion in the legion, gave the order to form the testudo, and in a moment a wall of shields surrounded the cohort and covered its top. Immediately the pace of the advance slowed, but the men were now protected from the missiles pelting them from above, and they rattled harmlessly off the broad curves of their shields. The clatter of the impacts was clearly audible down where Vespasian and his staff stood.