For an instant, the shah’s furious expression faded. His eyes softened as he stared at his eldest son.

‘I have never doubted your courage, Jelaudin.’

He reached out and gripped his son’s neck, pulling him into a brief embrace. As they parted, Ala-ud-Din sighed.

‘But I will not throw away your life. You will come with me and next year we will bring four times as many warriors to root out these godless invaders. I will arm every man who can hold a sword and we will bring fire and bloody vengeance on their heads. The Assassins will have killed their khan by then. For so much gold, they will move quickly.’

Jelaudin bowed his head. In the darkness outside the tent, he could hear the noises of the camp and the moaning of wounded men.

‘We leave tonight, then?’

If the shah felt the sting of dishonour, it did not show.

‘Gather your brothers. Hand command to the most senior man left alive. Tell him…’ He trailed off, his eyes growing distant. ‘Tell him that the lives of our men must be sold dearly if they are to enter paradise. They will be frightened when they find I have gone, but they must hold.’

‘The Mongols will track us, father,’ Jelaudin replied, already thinking of the supplies he must take. He would have to gather his father’s mounted guard as quietly as possible, so as not to alarm those they left behind.

The shah waved a hand irritably.

‘We will go west, away from them, then cut north and east when we are clear of Otrar. The land is vast, my son. They will not even know we are gone until tomorrow. Gather what we need and come back here when you are ready.’

‘And Otrar?’ Jelaudin said.

‘Otrar is lost!’ the shah spat. ‘My cousin Inalchuk has brought this disaster on us, and if I could kill the fool myself, I would.’

Jelaudin touched his forehead, lips and heart with his head bowed. His dream of riding at the head of a victorious army had been crushed, but he was his father’s son and there would be other armies and other days. Despite the humiliation and horror of the battles against the Mongols, he thought nothing of the lives given for his father. They were the shah’s men and any one of them would die to protect him. As they should, Jelaudin thought.

He worked quickly as the moon passed overhead. Dawn was not far away and he needed to be well clear of the battle and the Mongol scouts by the time it came.

Genghis waited in the moonlight, dark ranks of men at his back. Khasar was with him, but neither brother spoke as they stood ready. The scouts had warned them of the Otrar garrison coming in. Even then, it had been barely in time to beat back the night attack on their camp. Behind him, Genghis had given command to Tsubodai, the most able of his generals. He did not expect to get any sleep before the morning, but that was common enough to the warriors around him and, with meat, cheese and fiery black airag, they were still strong.

Genghis cocked his head at a sound from the gloom. He clicked with his tongue to alert the closest men, but they too had heard. He felt a pang of regret at the deaths of Samuka and Ho Sa, but it passed quickly. Without their sacrifice, he would have lost it all the day before. He turned his head left and right, searching for more sounds.

There. Genghis drew his sword and all along the line the front rank readied lances. They had no arrows with them. Tsubodai had spent much of the night collecting the final shafts into full quivers, but they would need them when dawn came. Genghis could hear walking horses ahead and he rubbed tiredness from his eyes with a free hand. At times, it seemed as if he had been fighting all his life against these dark-skinned madmen.

With Jelme, he had chosen a spot to wait just under a low rise. Even in the moonlight, he would not be seen, but his scouts kept moving, leaving their horses and running in the dark to keep him informed. One of them appeared at his stirrup and Genghis dipped his head to hear the soft words, grunting in surprise and pleasure.

When the scout had gone, Genghis nudged his horse close to Khasar.

‘We outnumber them, brother! Samuka and Ho Sa must have fought like tigers.’

Khasar nodded grimly.

‘It’s about time. I am tired of riding against their vast armies. Are you ready?’

Genghis snorted.

‘I have been waiting for ever for this garrison, brother. Of course I am ready.’

The two men parted in the darkness, then the Mongol line surged forward over the rise. Against them, the remnants of the garrison of Otrar were making their way south to join the shah. They came to a shocked halt as the Mongol lines appeared, but there was no one to save them as the lances came down.

Shah Ala-ud-Din reined in as he heard the sounds of battle echo back from the hills. In the moonlight, he could see distant smudges of fighting men, but he could not guess what was happening. Perhaps the cursed Mongols had attacked again.

With only four hundred surviving riders, he and his sons had abandoned the army and ridden hard. The shah glanced at the east and saw dawn was coming. He tried to fill his mind with plans for the future, numbing it to regrets. It was difficult. He had come to smash an invader and instead seen his best men bleeding out their strength. The Mongols were tireless killers and he had underestimated them. Only the thought of Abbas riding to the Assassins’ stronghold in the mountains gave him satisfaction. The men of shadows never failed and he only wished he could see the face of the khan as he felt their soot-blackened knives plunging into his chest.

Kokchu could smell fear in the camp, thick in the warm night air. It showed in the lamps that hung from posts at every intersection in the maze of gers. The women and children were afraid of the dark, with imagined enemies all around them. For Kokchu, the simmering terror was intoxicating. With the maimed warriors, Genghis’ brother Temuge and Yao Shu, he was one of very few men left among thousands of frightened women. It was hard to hide his arousal at their flushed faces. He saw them prepare as best they could for an attack, stuffing clothes and armour with dried grasses before tying them to spare mounts. Many of them came to him each day, offering whatever they had so that he would pray for their husbands to come back safe. He guarded himself rigidly at those times, forcing himself to remember that the warriors would return and ask their wives about the time alone. As young women knelt and chanted before him in his ger, their pathetic offerings lying in the dust, he sometimes placed his hand on their hair and grew flushed as he led them in their entreaties.

The worst of them was Genghis’ sister, Temulun. She was lithe and long-legged, an echo of her brother’s strength in her frame. She had come three times to ask for his protection over Palchuk, her husband. On the third, the smell of sweat was strong on her. While small voices screamed warnings in his head, he had insisted on placing a charm on her skin, one that would extend to all those she loved. He felt himself grow hard at the memory, despite his misgivings. How she had looked to him with hope in her eyes. How she had believed! Having her in his control had made him reckless. He had told her of a most potent charm, one that would be like iron against enemy swords. He had been subtle in his doubts and in the end she had begged him for its protection. It had been hard to hide his excitement then as he bowed to her need.

She had removed her clothes at his order, standing naked before him as he began the chant. He recalled the way his fingers had shaken as she closed her eyes and let him daub her body in a web of sheep blood.

Kokchu stopped his meandering path and swore to himself. He was a fool. At first, she had stood proud and still, her eyes closed as he drew lines with a finger pressing into her flesh. He had marked her in wavering red until her stomach and legs were criss-crossed with patterns. His lust had been overwhelming and perhaps he had begun to breathe too hard, or she had seen his flushed face. He winced at the thought of her feeling him press against her thigh as he leaned close. Her eyes had snapped open from the trance, looking through incense smoke and suddenly doubting him. He shuddered as he recalled her expression. His hand was lingering over her breasts, marking them in shining blood, the scent of which filled his nostrils.