A couple of auxiliaries fell, shields dropping, and it took a moment for their comrades to pull them back under cover. With a crack like a whip, the first ballista spat out a bolt which drove deep into a horse’s head. The animal’s front legs collapsed and the rider was flung forward through the air. The second engine shot, but missed as an archer swayed down from his saddle so that he was almost clinging to the side of his horse. From behind the infantry, a dozen or so of the auxiliary cavalry galloped forward, raising a strange ululating cry as they did. Caught from two sides, the horse archers scattered, some going left and some going right. One of the carroballistae sent another dart, which struck a rider squarely in the back and pitched him out of the saddle. His horse galloped on with the others.

The drab-clothed rider headed away from the Brigantes, twisting round to shoot back at them. The first arrow went high, the second was short, flicking through the thin grass just ahead of Ferox. Then the man realised that the auxiliaries were pressing from the other side and spun around to escape to the right. Bran threw a javelin and hit him in the small of the back. He slumped forward, dark blood spreading from the wound, and managed to cling onto the neck of his horse. Ferox saw a brightly dressed rider wearing a cuirass of mixed silvered and gilded scales on a tall black horse, but the man was already too far away for there to be much chance of catching him, so he swerved left, kicking his horse onwards, and the beast stuttered into a faster gallop, hoofs pounding across the hard earth. The archer and another were crossing his path, and the nearest saw him, flicking his bow around to shoot. Ferox felt a blow on his shoulder as the arrow nicked his mail before skidding off. The distance closed very, very fast, and the archer half-cowered because there was no time to draw his sword. Ferox’s horse barged with his shoulder against the other man’s mount, and he cut down and to the right, feeling the blade hit bone high just below the shoulder. The rider fell, his horse swerved into his companion, who checked, before speeding away. Ferox slapped his horse with the flat of his blade. ‘Come on!’ he urged her, and he leaned forward, knowing that there would be just one chance before the second archer’s pony hit its stride and left him behind. Aiming carefully he lunged into the small of the man’s back, heard him scream as he tried to arch away from the pain, and Ferox almost lost his balance, falling hard with his weight against the saddle horns. His mare gave in, slowing and then stopping, and that gave him the chance to pull himself up.

A few of his men and some of the auxiliaries were still chasing after the horse archers, but already the gap was widening. The enemy were good, or at least quite good. He doubted that a band wholly of Roxolani or, from all he had heard, of Dahae or Saka, would have been ambushed so easily. The brightly dressed leader was still with them, his strong horse carrying him to the front of the swarm of fleeing men, and Ferox thought it was the prince they had seen outside Nicopolis, although at this distance he could not be sure.