To his left, Valens saw Iudex step forward. With a practised economy of movement, the bald soldier flicked the spears of his two opponents aside, and stepped inside their reach.

Valens had no more time to watch. His assailant thrust again. This time he gave no ground. Balanced on the balls of his feet, he blocked the attack. The nomad’s momentum brought him crashing into Valens. Locked together, they tottered a couple of steps. The rank stink of the man was choking. Fingers stiff, Valens drove his nails into the tent-dweller’s bearded face. They missed the eyes, but raked the flesh. The nomad reared away, howling. With the strength of desperation, Valens thrust his sword into the man’s stomach. A split second of resistance, then the steel slid in easier than into the carcass of a chicken.

The reek of hot blood and faeces filled the air.

Still holding the torch in one hand, Iudex was standing over his two victims.

‘More coming,’ Iudex said.

By the flickering light of the burning tent, they saw a throng of nomads filling the opening to the alleyway. It would be no time before they thought to work around the shelters, and take the two men from the rear.

‘Give me the torch,’ Valens said.

Wordlessly, Iudex handed it over.

Valens swished the brand until it flared again. He judged the distance, then, not pausing to think further, ran three or four steps forward. He hurled the torch overhand. It cartwheeled over the nearest tents, trailing sparks.

The throw was good. The torch landed amid the camels, hitting one on the flank as it fell. Maddened by pain and fear, the beast wrenched the peg that secured its tether from the ground. It blundered into the next in the line. At once all the camels were roaring and struggling, boring into each other. One went down. As it went to get up, its legs fouled those still on their feet.

Nothing was more precious to the nomads than their camels. Jabbering with concern, the crowd of men facing the two Romans rushed to their aid.

‘Run,’ Iudex said.

Holding his scabbard in his left hand to keep it from tangling in his legs, the hilt of his blade still grasped in his right, Valens ran. Terror gave wings to his feet. Even so, Iudex was drawing ahead.

The respite was temporary. All too soon, Valens heard the shouts of his pursuers.

He ran on, his breath torn, rasping from his throat, his lungs scorching.

It was no more than two hundred paces to the depression where Narses and the others waited. It might as well have been miles. There was no sight of them, or even of Zabda and the woman. Just the blue cloak of Iudex swirling in the expanse of the night.

The nomads were gaining. Their unearthly ululating cries echoing in the darkness.

Valens glanced back. They were but thirty paces behind.