Alexios was beside the eparch, trying to haul him across his horse’s withers. Arab horsemen were appearing out of the broken ground below them. Another arrow fizzed between Erlan and the commander.

‘Leave him! He’s finished,’ cried Erlan.

Alexios gave one more desperate haul at the envoy but his mount shied away and the eparch’s obese corpse crashed to the ground. The fastest of the Arab horsemen were kicking on across the contour of the slope to head them off.

‘Ride north-west,’ screamed Alexios, drawing his sword. ‘All of you – get clear, for God’s sake!’

Erlan squeezed his knees and his mare took off down the rocks. Beside him, Aska barked and bounded on. Davit and the other guard – a man named Bringas – were weighed down with saddlebags stuffed with gold and other treasures for the Bulgar khan. They had a head start down the slope but Erlan and the Fat-Belly were gaining on them quickly.

Seeing the two front riders of the Arab patrol bearing in from the left, Erlan turned to come between them and the gold. As the gap closed he saw they were dressed in scale armour and billowing green breeches with long lances lowering for the kill. He bent close over his horse’s ears, half-praying the riders were too intent on the easier prey to see him slanting in at their flank.

The lance-tip of the closest was only yards from catching Davit when Erlan bellowed a war cry. The Arab turned and twisted his body; seeing the danger, his spear-tip swung to meet Erlan. He lifted his shield and took the blow on its boss, which nearly vaulted him from the saddle, but grinding his knees tighter into the horse’s flesh he kept his seat. He was inside the point now, his horse barrelling along beside the Arab, shoulder to shoulder down the narrow path. Erlan held his shield out, twisted in his saddle and swung his sword arm like an axe. He had a split second to see the horror in the Arab’s eyes and then his head was gone, bumping away into the mud. Erlan punched with his shield, and the headless body tipped over and fell like a broken doll against a rock.

He heard a yell behind him and stole a glance back to see Alexios wheeling his horse to meet another lancer driving in from the left. Erlan sawed on his reins and yanked his filly’s head round, then kicked her on up the slope. This was a bloody mess. But there was no use others dying now.