Marcus urged his mount into a gap between two of the riders and made for a man with a spear who had worked his way round behind Festus and was raising the weapon to strike. Leaning forward in his saddle, Marcus slashed his sword at the butt of the spear, knocking it down so that the tip swished harmlessly over Festus’s shoulder. The leader of Caesar’s bodyguard caught the blur out of the side of his eye and instantly wheeled his horse round, slashing down at the man who had tried to kill him, and laying open his arm. Another cut to the shoulder put the brigand out of action.

Meanwhile Caesar was surrounded by Mandracus s men and he pulled hard on the reins to make his horse rear up and lash out with its hoofs, forcing his opponents back. It was impossible to keep them all at bay and even as Marcus watched, he saw one of them stab a pitchfork into the horse s rump. A shrill whinny cut through the air and the beast lashed out with its rear legs, catching the man to send him flying. Marcus flicked his reins and drew up alongside Caesar, lashing out with his sword to keep the others back. Caesar acknowledged his presence with a swift nod.

‘We have to get out of here. Those horsemen will join the fight any moment.’

Marcus glanced round, past the men locked in combat, and saw the other riders racing up the incline towards them, no more than a hundred paces away. Once they reached the pass it would all be over.

‘Festus!’ Caesar called out above the din of the fight. ‘All of you, on me! On me! We must cut our way through!’

The bodyguards edged their mounts closer to Caesar and formed a loose ring. Looking round, Marcus could see that one was missing, and then he saw a group of brigands bending towards the ground beside a horse with an empty saddle. They were hacking and stabbing at the man on the ground, their weapons dripping with blood each time they came up for another blow. The bodyguard with the wounded leg was swaying in his saddle and moaning through clenched teeth as blood coursed from his wound, splashing on to the snow like exotic flowers. Lupus, who had managed to stay with Marcus, held his dagger up as a snarl distorted his features.

Mandracus had worked his way round to return to his position astride the road leading into the pass. He bellowed to his men to form up either side of him. Those who could did as f they were ordered, chests heaving as their breath plumed in the freezing air.

Caesar glanced round at his men, then thrust his sword I forward. ‘Stop for nothing! Go!’

The small party of riders burst into a gallop, and at the last moment the courage of the brigands failed and most tried to dive out of the way. A handful of the braver men stood by their leader, weapons levelled as the horses charged into them and they were either cut down or trampled. Only Mandracus remained on his feet, swinging his axe from side to side, forcing the nervous riders to swerve round him. Beyond, the road was open and Marcus briefly dared to hope they had escaped. He glanced back and saw Lupus behind him, cloak flickering wildly as he hunched over his saddle, still holding the dagger aloft.