He looked along the shore to where the gers clustered, covering miles of land around the lake. It was a good place, but the grazing was very poor and the goats and sheep that fed them had to be walked back to slaughter each day. It was time to move on, he thought, enjoying the idea. His people were not made to stay in one place, with just one view, not when the world stretched around them with an infinite array of strange things to see. Genghis arched his back, feeling it click unpleasantly He saw another rider setting out from the gers and sighed to himself. Though his eyes were not as sharp as they had once been, he knew his brother Kachiun from the way he rode.

Genghis waited for his brother, enjoying the breeze coming off the water as the sun beat down. He did not turn as Kachiun called a greeting to Sorhatani and the boys.

‘You have heard then?’ Genghis said.

Kachiun came to stand by him, looking out over the same pale waters.

‘The scouts? I sent them to find you, brother. They have found Jochi, but that is not why I am here.’

Genghis did turn then, raising his eyebrows at his brother’s serious expression.

‘No? I thought you would be full of advice on how I should deal with my son the traitor.’

Kachiun snorted.

‘Nothing I can say will change what you do, Genghis. You are khan and perhaps you should make an example of him to the rest; I don’t know. That is for you to decide. I have other news.’

Genghis studied his brother, seeing how his once smooth face had taken on lines around the mouth and eyes. The age showed most when he smiled, which was less and less often since coming to Arab lands. Genghis owned no mirrors of the sort the Chin made, but he supposed his own face was just as weathered, or even more.

‘Tell me then, brother,’ he said.

‘You have heard of this army in the south? I have had men watching it for some time.’

Genghis shrugged.

‘Tsubodai and Chagatai have both sent men to watch them. We know more about that gathering of farmers than they do themselves.’

‘They are not farmers, Genghis, or if they are, they have the armour and weapons of soldiers. The latest reports are of sixty thousand men, if my scouts have learned to count so high.’

‘I should fear only sixty? They grow, then. We have watched them for a year or more. They shout and chant and wave their swords. Are they coming for us at last?’

Genghis felt a cold hand clutch at his belly for all his lightness of tone. He had heard of the gathering army and their revered leader almost a year after he had returned from the Assassins’ stronghold. His generals had prepared for attack, but the seasons had crept by and no army had marched against them. At times, he thought it was only the threat of them that kept him in lands where heat and flies bothered him every day.

‘My men captured three of their number,’ Kachiun answered, interrupting his thoughts. ‘They were wild, brother, almost frothing at the mouth when they realised who we were.’

‘You made them talk?’ Genghis said.

‘We could not; that was what surprised me. They merely spat threats at us and died badly. Only the last gave me anything and that was the name of the man who leads them.’

‘What do I care for names?’ Genghis asked incredulously.

‘You know this one: Jelaudin, whose father was the Shah of Khwarezm.’

Genghis stood very still as he digested the information.

‘He has done well. His father would be proud of him, Kachiun. Sixty thousand men? At least we know for sure that he will come north, after my head. There will be no more talk of purges into India, not now we know it is Jelaudin.’

‘They cannot move a step without me knowing, brother.’

‘If we wait for them,’ Genghis said thoughtfully. ‘I am tempted to end their shouting with my tumans.’

Kachiun winced, knowing that if he were to guide Genghis, it would have to be subtle.

‘The shah’s army was far larger, but we had no choice then. Your own tuman and mine are proven. Tsubodai’s Young Wolves and Jebe’s Bearskins bring twenty thousand more to the field. Chagatai, Khasar and Jelme another thirty. Seven tumans of veterans. Ogedai is barely blooded. I would not want to throw his men against such an enemy.’

‘I gave him good officers, Kachiun. They will not let me down.’

Genghis considered the gers along the shore. The families bore children in the thousands each year, but many of them went into the tumans to replace the dead and injured. It had been difficult to create a new tuman for Ogedai, but his heir had to learn command and the other generals had gone begging for a year. He did not mention his plans to form a ninth tuman for Tolui to lead. His youngest son’s wife had approached him on the subject just a few months before. Genghis glanced over to where she now played with Kublai and Mongke, tossing one after the other into the water, to their delighted shrieks.

‘Find a good second for Ogedai, Kachiun. Someone who can stop him doing something stupid until he learns.’

‘Even then, eight tumans against almost as many?’ Kachiun replied. ‘We would lose many good men.’ He hesitated and Genghis turned to him.

‘You have not worried about numbers before, brother. Spit it out, whatever it is.’

Kachiun took a deep breath.

‘You brought us here to avenge men killed by the shah. You have done that and repaid their deaths a thousand times over. Why should we stay and risk destruction? You do not want these lands and cities. How long is it now since you saw the mountains of home?’ He paused to gesture at the peaks around the lake. ‘This is not the same.’

Genghis did not answer for a long time. When he spoke at last, he weighed each word carefully.

‘I brought the tribes together to take the Chin foot off our necks. Then I took it off and we humbled their emperor in his capital. That was my path, the one I made and chose and fought for. I wanted to send the Chin reeling still further, Kachiun, right to the sea in all directions. I would not even have come here if they had not provoked me. They have brought this on their own heads.’

‘We do not have to fight the entire world,’ Kachiun said quietly.

‘You are getting old, Kachiun, do you know that? You are thinking of the future, of your wives and children. Don’t splutter, brother, you know I am right. You have forgotten why we do this. I was the same for a time in Samarkand. I told Arslan these people live longer than us and have safer, softer lives. They do, just as camels and sheep live happily on the plains. We could choose that for a time, though wolves would still come for us in the end. We are herdsmen, Kachiun. We know how the world truly works and everything else is just an illusion.’

He looked over to his grandsons, seeing Sorhatani comb their hair as they writhed and struggled to get away from her. Her own hair was long and black and he toyed with the idea of getting himself another young wife like her to warm his bed. It would invigorate him, he was certain.

‘Brother,’ he said, ‘we can live our lives at peace, so that our sons and grandsons can live their lives at peace, but what is the point? If we all live to eighty in a green field, without ever holding a bow or sword, we will have wasted the good years. You should know the truth of that. Will our grandsons thank us for a peaceful life? Only if they are too afraid to take up arms. I would not wish a quiet life on my enemies, Kachiun, never mind my own family. Even cities only prosper when there are rough men on the walls, willing to stand and die so that others can sleep in peace. With us, we all fight, from the first yell to the last breath. It is the only way to take pride in who we are.’

‘I do take pride!’ Kachiun snapped. ‘But that does not mean…’

Genghis raised a hand.

‘There is no “but”, brother. This Jelaudin will sweep north with his men and we could run before them. We could let him take back every city we have won and call himself shah in his father’s place. He might think twice before provoking me again when I send envoys to him. But I came to these lands because, when a man threatens me and I look away, he has taken something important from me. If I fight and die, all he can take is my life. My courage, my dignity remains. Shall I do less for the nation I have made? Shall I allow them less honour than I claim for myself?’