The Selgovae were walking down the slope, most of them coming in ranks, side by side, banging weapons on their little shields and chanting something that might have been a word and might have been a grunt over and over again. The warrior in the striped cloak was in the middle, and beside him was another, bare-chested man, taller and broader, with streaks of grey in his long brown hair. He carried a big rectangular shield, its battered and scarred surface still showing the thunderbolt symbols of Legio XX, but painted over with a charging boar. Just behind them someone carried a standard with a bronze cockerel at the top.

‘Steady, lads, back another step.’

A couple of Britons ran out from the front of the formation, javelins poised to throw.

‘Keep it steady, lads. Shields braced, back another pace.’ One of the auxiliaries in the third rank slipped and fell with a loud curse. Javelins thumped into the shields of the men in front, one driving through the board of the shield and sending a splinter to graze the man’s face.

Ferox glanced back. The shape of the valley side was less even than he had thought and rose behind him in a low spur, so that he could no longer see the Roman camp. He had no idea whether or not help was coming. The wounded men were being carried across a little gully just in front of the low spur. The Selgovae kept up their chant, the noise getting louder and louder, so that it almost seemed to punch at them. Ferox was about to turn back to judge whether he had time to run faster before re-forming again when there was a flicker of movement on the spur. A man appeared, almost doubled up in a crouch, spear and shield held low as he came on to the low rise. It was too far away to see, but Ferox could sense the man smile as he stood up. The warrior was naked save for a cloak, his body scored with lines and circles of blue woad, and as he brandished his spear in the air dozens and then scores of men answered his shout and poured over the spur.

‘Orb!’ Ferox shouted. ‘Form an orb, two ranks deep! Move!’ It was not the order they were expecting, but long practice or instinct took over and the Tungrians in the rear rank faced about and stepped forward, the men in the middle going faster. The front ranks bent back on the flank and in a moment they formed a very rough circle. Ferox was in the middle, pulling men from the second rank to strengthen the sides and rear, shouting and shoving to get them into place. One of the auxiliaries grunted as a javelin came over the top of his shield and drove through the reinforced mail on his shoulder. Ferox pulled the man back into the middle of the formation.