It was nearly an hour later before the vanguard emerged from the distant haze of rolling hills and forest. A faint rippling glitter marked the first of the cohorts as the sun caught on polished helmets and weapons. Slowly, the head of the distant legion resolved itself into a long column, like a many-scaled serpent languidly slithering across the landscape. Mounted staff officers cantered up and down each side of the column, ensuring that nothing held up the regular, disciplined pace of the advance. On each flank, some distance from the legion, more scouts guarded against any surprise attack from the enemy. Towards the rear trundled the dark mass of the baggage and artillery trains, then finally the afterguard cohort. Cato was surprised by the size of the artillery train. It was far larger than the usual complement for one legion. Somehow the legate must have wangled himself some reinforcements. Good, thought Cato, as he glanced across at the hill fort. They would be sorely needed.

‘It’s time we had a word with Vespasian,’ Cato muttered, then tapped Prasutagus on the head with his boot. ‘Down, boy!’

They hurried from the crest of the hill to find Boudica, and Cato told her the news. Then, they cautiously emerged from the forest and made their way east towards the approaching legion. They passed a handful of small hovels, where in more peaceful times peasant farmers eked out a living growing crops and raising sheep and pigs, maybe even cattle. Now they were empty, all the farmers, their families, and their animals sheltering inside the Great Fortress from the terrifying invaders who marched under the wings of their gold eagles.

Cato and his companions passed the place where the Druids’ wagon had been taken a few days earlier, and saw that there was still blood, dry and dark, encrusted on the wagon ruts. Once again Cato thought of Macro, and felt uneasy about the prospect of discovering the centurion’s fate when they reached the legion. It seemed impossible that Macro could die. The latticework of scars the centurion bore on his skin, and his boundless confidence in his indestructibility, bore testimony to a life that, while fraught with danger, was peculiarly charmed. It was easy to visualise Macro old and bent in some veterans’ colony many years from now, endlessly recounting tales of his army days and yet not too old to get drunk and enjoy a geriatric punch-up. It was almost impossible to imagine him cold and dead. And yet that wound to his head, with all its appalling severity, threatened the worst. Cato would find out soon enough, and dreaded it.

The scouts appeared as they were crossing the trestle bridge. A cocky looking decurion — all fresh plumes and knee-high soft leather boots — cantered down the slope towards them, flanked by half of his squadron. The decurion drew his sword and bellowed the order to charge.