Abbud waited, sweating, listening to strange noises. The warriors came back almost as quickly and he did not miss the looks of anger they turned on him. The young Bedouin took Abbud by the arm, his grip almost painful.

‘Old man, this is not a night for games, do you understand? I have searched stables for half a night waiting for you. Now you have led me to an empty house. It will be hard for me to stop them killing you.’

Abbud winced, but he did not try to pull away.

‘They were here! It is my brother-in-law’s house and he talked of them in the markets. Four young men and an old one who was very sick. That is all I know, I swear it.’

In the moonlight, the Bedouin’s eyes were in shadow, his face colder than the night. He let Abbud’s arm fall, then exchanged a flurry of words with Tsubodai that Abbud could not understand.

The one Abbud had marked as leader stared at the old jeweller for a long moment of silence. Then he gave new orders. Abbud could only stand and watch as the warriors kicked in other doors and the night was broken with screams. A struggle started in a house nearby and Abbud cried out in shock as one of the warriors drew his sword and killed a young man with a thrust to his heart, stepping over him to search his home.

‘There is no need for this!’ Abbud shouted. ‘They are not here!’

The Bedouin turned to him and to Abbud’s astonishment seemed to be smiling.

‘I cannot stop them now, old man. They will search every house in the street, perhaps the whole town. Then they will burn Khuday down around you.’

It was too much for the jeweller.

‘There are stables nearby. If they have gone anywhere, it is there.’

‘Take me there, old man,’ the Bedouin said. ‘If you are right, perhaps Khuday will not be destroyed.’

Jelaudin brought his horse to a clump of straggly bushes on the crest of a hill. The air was sweet with the scent of lemon leaves and his heart was heavy as he looked back at the town that had sheltered them. On his right hand, the North Star shone in the heavens, the air clear and bright.

To the east, far away, he could see the fires of the Mongol camp as a dim glow. To the west, the Caspian Sea waited, a final barrier to his fleeing family. He knew he could not ride along its banks for a hundred miles with the Mongols searching for them. They would be caught as easily as running hares. He felt the east as a hunger, desperate to return and seek out the cities he had known as a boy.

The night was still and his father’s tortured breath hurt him to hear. Jelaudin and his brothers had tied the old man to his saddle and led his horse out of the town, heading across scrub wasteland and avoiding the eastern road.

If the Mongols had been certain they were in Khuday, they would have surrounded the city. As it was, the sons of the shah had walked their horses away from the town and not seen a living soul. Yet escaping such a place was a small thing. If they could not turn south, the sea would trap them as surely as any net. As his father’s wheezing intensified, Jelaudin was overwhelmed for an instant. He was too tired to run again, too tired even to mount.

His brother Tamar heard the sound of his weeping and laid a hand on his shoulder.

‘We must go, Jelaudin,’ he said. ‘There is always hope while we live.’

Jelaudin nodded despite himself, rubbing at his eyes. He swung a leg into his saddle and took the reins of his father’s horse. As they moved away into the darkness, he heard Tamar gasp and looked back at Khuday.

The town gleamed in the night. At first, Jelaudin could not understand the strange light that flickered over the huddled streets. He shook his head as the light spread and knew the Mongols were burning the town.

‘They will glut themselves on that place until dawn,’ another of his brothers said.

Jelaudin heard a note of triumph in the younger man’s voice and wanted to strike him for his foolishness. He wondered if Abbud and his servant boy would survive the flames they had brought to Khuday, as if the brothers trailed pestilence and destruction in their wake.

There was nothing to do but ride on to the sea. Though he felt his own death like dark wings beating at him, Jelaudin kicked in his heels and made his horse trot down the slope beyond.

The brothers led their father’s horse for four more days before they saw riders following them. They could not hide their tracks on the dusty ground and Jelaudin had known they would be followed, though he had still clung to thin hopes that the Mongols would miss them. He had ridden to exhaustion through night and day until he could smell the salt of the sea ahead and hear the calls of gulls. For a time, the clean air had revived them all and then he had seen dark figures in the distance, a mass of warriors on their trail, riding them down.

Jelaudin looked at his father’s waxy face. There had been no time to stop and make a fire for the bitter herbs and the old man’s condition had worsened. More than once, Jelaudin had pressed his ear to his father’s lips, listening to see if he still breathed. He could not leave him to be torn apart by these hunting dogs of the khan, but his father slowed them all.

For a moment, Jelaudin wanted to roar out his hatred and terror at the distant lines of those hunting him. He hardly had the strength even for that and he shook his head wearily, looking up as he and his brothers passed over a sandy dune and saw the shimmering blue vastness of the sea ahead. Darkness was coming and they would have one more night before the Mongols found and killed them. Jelaudin looked along the shore and saw just a few huts and fishing boats. There was nowhere to hide and nowhere they could run any longer.

He ached as he dismounted and his horse shivered as his weight was removed. The animal’s ribs were showing and Jelaudin patted the mount’s neck for its faithfulness. He could not remember when he had last eaten and light-headedness made him stagger.

‘Are we to die here, then?’ one of his brothers asked plaintively.

Jelaudin barely grunted in reply. He had set out strong and young, losing men and strength at every turn for the best part of a year. He felt old as he stood on the shore, taking a piece of grey rock and casting it into the salt water. The horses dipped their heads to drink and Jelaudin did not bother to pull them away. What did it matter if they drank salt when the Mongols were coming to kill the sons of the shah?

‘I will not stand here and wait for them!’ Tamar was the next in age after Jelaudin. He strode up and down the sandy ground, straining his eyes for a way out. With a sigh, Jelaudin eased himself down to the ground and dug his fingers into its dampness.

‘I am tired, Tamar,’ he said. ‘Too tired to rise again. Let it end here.’

‘I will not!’ his brother snapped. Tamar’s voice was hoarse from lack of clean water, his lips cracked and lined with blood. Even then, his eyes were bright in the evening sun. ‘There is an island out there. Can these Mongols swim? Let us take one of the fishing boats and smash the others. We will be safe then.’

‘As trapped animals are safe,’ Jelaudin said. ‘Better to sit and rest, brother.’

To his amazement, Tamar stepped close and slapped him hard across the face.

‘Will you see our father butchered on this beach? Get up and help me put him in a boat, or I will kill you myself.’

Jelaudin laughed bitterly without replying. Nevertheless, he stood almost in a daze and helped his brothers carry the shah to the shore. As he struggled through the damp sand, he felt some life come back to his limbs and some of the despair seep away.

‘I am sorry, brother. You are right,’ he said.

Tamar only nodded, still furious.

The fishermen came out of their driftwood huts, shouting and gesturing as they saw the young men hammering at their boats. The sight of drawn swords reduced them to sullen silence, standing in a knot of fury as they watched the strangers break the single masts, batter holes in the hulls and then push them into deep water so that they vanished in frothing bubbles.