‘This is a warning,’ Tsubodai said.

Genghis shrugged.

‘A warning or a punishment. Someone saw you talking to the merchant.’ He chuckled at the thought of the man’s oblivious approach with a cart full of gold. His sudden wealth would be worth nothing in that place.

‘We could find the same in the village further into hills that he spoke of, his sister’s home.’

Genghis nodded. He did not care particularly that villages had been destroyed. If the burned houses were meant as a warning, there were few men in the world who could have taken it as lightly as he did. He had seen much worse in his years as khan. That thought reminded Genghis of something his mother used to say when he was a boy and he smiled.

‘I was born with a clot of blood in my right hand, Tsubodai. I have always walked with death. If they know me at all, they know that. This destruction is not a warning for me, but for anyone else who might consider dealing with me.’ He frowned to himself then and drummed his fingers on his saddle. ‘It is the sort of thing I might do if I were leaving the area.’

Tsubodai nodded, knowing the khan did not need to hear his agreement.

‘Still, we must push on to see where they hid themselves,’ Genghis said, his mood souring, ‘even if they have abandoned it.’

Tsubodai merely bowed his head and whistled for the scouts to ride with him into the mountains. The sister’s village was a day’s trek for a fast-moving warrior, perhaps three for the carts. The trails needed to be checked at all points for ambushes and Tsubodai had to resist the urge to race ahead and see if the Assassins had left anyone behind. The mountains were steep beyond that point, with only a narrow path leading the scouts through to the deep valleys and peaks. It was a difficult land to assault and worryingly easy to defend. Even sound was muffled in such a place, swallowed by the steep slopes on either side, so that a horse’s hooves could be heard as echoes, while the rest of the world receded. Tsubodai rode warily, his hand always near his bow and sword.

Jochi halted his tuman when he heard a warning note from his scout horns. He had ridden hard for more than a month, covering a vast distance into the east, so far that he was convinced the plains of his home lay a thousand miles north. Beyond them the world was endless, unmapped even by Tsubodai.

Jochi had known his father would send men after him eventually. Part of him had considered turning north before this point, though it would hardly have mattered. All the scouts could track a single rider, never mind the seven thousand who formed his tuman. The trail they left could have been followed by a blind man. If rains had come, their hoofprints would have been washed away, but to Jochi’s frustration, the sky had stayed cold and blue all the way, with barely a wisp of cloud.

His warriors allowed their ponies to crop the dry grass at their feet as they waited for new orders. Until they came, they were content and relaxed, giving no more thought to the future than a pack of wild dogs. Jochi did not know if they guessed at his internal struggle. At times, he thought they must know. Their eyes seemed aware, but he knew that was probably an illusion. As the khan’s scouts came closer, Jochi summoned his officers, from those who commanded a thousand down to those who led just ten. They had all stood in the palace at Samarkand and taken an oath to honour Ogedai as khan, the words still fresh in their minds. He did not know what they would do.

More than seven hundred came at his order, walking their mounts apart from those they led. Each had been promoted by Jochi himself, given honour with the trust of other lives in their hands. He felt their questioning gazes on him as he waited for his father’s scouts. His hands shook slightly and he stilled them with a tight grip on his reins.

The scouts were two young men from Genghis’ own tuman. They wore light deels, made dark and greasy by sweat and constant use. They rode in together and dismounted to bow to Genghis’ general. Jochi sat his horse in stillness, a great calm sweeping over him. He had believed he was prepared for this, but he had not been. Now the moment was finally upon him, he felt his stomach churn.

‘Deliver your message,’ Jochi said, looking at the closest man.

The scout bowed again, still relaxed and easy after a long ride.

‘The great khan has moved against the Assassins, general. He has good information as to where they have their stronghold. You are free once more to subdue the cities and widen the lands under his control.’

‘You have ridden far today,’ Jochi said. ‘You are welcome in my camp and you must stay to eat and rest.’

The scouts exchanged a quick glance before the first one replied.

‘My lord, we are not tired. We can ride again.’

‘I will not hear of it,’ Jochi snapped. ‘Stay Eat. I will speak to you again at sunset.’

It was a clear order and the scouts could only obey. Both men dipped their heads before remounting and trotting to the bulk of the tuman away from the gathering of officers. Rough cooking fires were already alight there and they were made welcome by those who cared for the freshest news.

Jochi raised his hand for his officers to follow him, angling his mount down a hill away from his warriors. A river ran along the bottom, shaded in old and twisted trees that overhung the water. Jochi dismounted and let his horse drink before reaching down and taking mouthfuls of the water in his cupped hands.

‘Sit with me,’ he said softly.

His men did not understand, but they tied their horses to the trees and gathered around him on the dusty ground until half the slope was filled with them. The rest of the tuman could be seen in the distance, too far to hear his words. Jochi swallowed nervously, his throat dry despite the water he had drunk. He knew the name of each of the senior men in that clearing by the river. They had ridden with him against the Arab horses, the shah’s army, cities and garrisons all. They had come to his aid when he was lost and alone amidst his brother’s warriors. They were bound to him with more than oaths, but he did not know if it would be enough. He took a deep breath.

‘I am not going back,’ he said.

To a man, the officers became still, some of them freezing in the act of chewing on meat or reaching for a skin of airag from their saddlebags.

For Jochi, saying the words was like a dam breaking. He sucked air in again as if he had been running. He could feel his heart pounding and his throat was tight.

‘This is not a new decision. I have thought this day might come for years, ever since I fought the tiger and we began our journey to these lands. I have been loyal to my father, the khan, in every action. I have given him my life’s blood and those of the men who followed me. I have given him enough.’

He looked around at the silent faces of his officers, judging how they received his words.

‘I will turn north after this. I have no desire to cross into the southern Chin lands, or go anywhere near Xi Xia in the east. I will see home again and be refreshed in streams that have given us life for ten thousand years. Then I will ride so far and fast that even my father’s hunting dogs will never find me. There are hundreds of lands still unknown to us. I saw some of them with general Tsubodai. I know him well and even he will not be able to find me. I will ride until the end of the world and make a home there, a kingdom of my own. There will be no tracks where I go. By the time my father even knows I am not returning, I will be lost to him.’

He could see the whites of the eyes in many of his men as they listened, stunned.

‘I will not order you to stay with me,’ he said. ‘I cannot. I have no family in the gers, while many of you have wives and children you would not see again. I make no demands on you, who are bound by oath to my father and Ogedai. You will be oath-breakers if you ride at my side and there will be no return to the nation, no truce with my father. He will send hunters and they will search for many years for us. He will not show mercy. I am his son and I know this better than anyone.’