Khasar wiped tears from his eyes and took a deep breath and a swig of airag from the bulging skin.

'He'll need walls at the new moon, I should think.'

Automatically, Kachiun looked to see if anyone could overhear them. They were surrounded by empty grass, with just their two ponies grazing nearby. Beyond them, warriors were busy in the sun, preparing for the great competition Ogedai had promised. There would be prizes of grey horses and armour for wrestlers and archers, even for those who won foot races across the plains. Everywhere they looked, men were training in groups, but there was no one loitering too close. Kachiun relaxed.

'You have heard something?'

'Nothing, but only a fool would expect the oath-taking to go without a hitch. Ogedai's not a fool and he's not a coward. He faced me when I was running wild after…' He hesitated and his eyes grew distant and cold for a moment. 'After Genghis died.' He took another swig of the harsh spirit. 'If he'd taken the oaths immediately, not a man in the tribes would have dared raise a hand to him; but now?'

Kachiun nodded grimly.

'Now Chagatai has come into his strength and half the nation wonders why he isn't going to be khan.'

'There will be blood, brother. One way or another,' Khasar replied. 'I just hope Ogedai knows when to be forgiving and when to cut throats.'

'He has us,' Kachiun said. 'That is why I wanted to meet here, to discuss our plans for seeing him safe as khan.'

'I haven't been summoned to his white city for my advice, Kachiun, have you? You don't know whether he trusts us more than anyone else. Why should he? You could be khan if you wanted. You were Genghis' heir while his sons grew.' Khasar saw his brother's irritation. The camp was full of such talk and both men were tired of it, but Khasar just shrugged.

'Better you than Chagatai, anyway. Have you seen him out running, with his bondsmen? So young, so virile.'

He leaned over the edge of the cart and spat deliberately on the ground. Kachiun smiled.

'Jealous, brother?'

'Not of him, though I do miss being young sometimes. Now some part of me is always aching. Old wounds, old knees, that time when you completely failed to stop me getting speared in my shoulder – it all hurts.'

'It is better than the alternative,' Kachiun said.

Khasar snorted.

They looked round as Jebe approached, with Tsubodai. Both of Genghis' generals were in their prime and Kachiun and Khasar shared a glance of private humour at the way they came striding confidently across the summer grass.

'Tea in the pot, meat in the bowl,' Khasar said without ceremony as they climbed the steps up to the old khan's ger. 'We are discussing how to keep Ogedai alive long enough for him to carry the white tails.'

The symbol of the united tribes still fluttered above his head, horsetails that had once been a riot of tribal colours, until Genghis had bleached them pale and made them one. No one had dared to remove the symbol of power, any more than they had queried Khasar's use of the cart.

Tsubodai made himself comfortable on the wooden edge, his feet dangling as he dug into the meat and bread. He was aware that both Kachiun and Khasar were waiting for what he would say. He did not enjoy the attention and he ate slowly and cleared his throat with airag.

In the silence, Jebe leaned back against the felt wall and looked at the city in the distance, a white haze in the warm air. He could see the golden dome of Ogedai's palace and it struck him that it resembled a yellow eye staring out of the city.

'I have been approached,' Jebe said. Tsubodai stopped chewing and Khasar put down the skin of airag as he was about to drink. Jebe shrugged. 'We knew one of us would be, sooner or later. It was a stranger to me, wearing no marks of rank.'

'Sent by Chagatai?' Kachiun said.

Jebe nodded. 'Who else? But no names were mentioned. They do not trust me. It was just a light touch, to see which way I would jump.'

Tsubodai grimaced. 'You jumped here, in full view of the tribes. No doubt they are watching you now.'

'What of it?' Jebe said, bridling. 'I was loyal to Genghis. Do I demand to be known by my birth name, as Zurgadai? I carry the name Genghis gave me, and I am loyal to the son he named as heir. What do I care who sees me talking with his generals?'

Tsubodai sighed and put aside the final piece of his meal.

'We know who is most likely to disrupt the oath-taking. We do not know how they will do it, or how many men will support them. If you had come to me quietly, Jebe, I would have told you to agree to anything they say and learn their plans.'

'Who wants to go creeping about in the dark, Tsubodai?' Khasar said scornfully. He looked to his brother for support, but Kachiun shook his head.

'Tsubodai is right, brother. This isn't just a matter of showing we support Ogedai and all right-thinking men following us. I wish it was. There was never a khan of the nation before Genghis, so there are no laws for how he passes on his power.'

'The khan makes the laws,' Khasar replied. 'I didn't see anyone complaining when he made us all take an oath to Ogedai as heir. Even Chagatai got down on his knees for that.'

'Because his choice was to fall flat or die,' Tsubodai said. 'Now Genghis is gone and the men around Chagatai are whispering in his ear. They are saying the only reason he was not heir was his struggle with his brother, Jochi, but Jochi is dead.'

He paused for a moment, thinking of the blood that had splashed on snow. His face was utterly blank and they could not read him.

'There are no traditions to tell us how to act,' Tsubodai went on wearily. 'Yes, Genghis chose his heir, but his mind was clouded with anger over Jochi. It was not so many years ago that he favoured Chagatai over all his brothers. The nation talks of nothing else. At times, I think Chagatai could press his claim openly and become khan. He could walk right up to Ogedai with a sword and fully half the army would not stop him.'

'The other half would tear him to shreds,' Khasar said.

'And in a stroke, we would have a civil war that would break the nation in two. Everything Genghis built, all our strength, wasted on an internal struggle. How long would it be then before the Chin rose against us, or the Arabs? If that is the future, I would rather see Chagatai take the horsetail banner today.' Tsubodai held up his hand as they began to protest. 'That is not a traitor speaking, do not think it. Have I not shown that I followed Genghis, even when everything in me cried out that he was wrong? I will not fail his memory. I will see Ogedai as khan, on my word.'

Once again, he thought of a young man who had believed his promise of safe passage. Tsubodai knew his word was worthless, where it had once been iron. It was an old grief, but on some days he bled as if he had just been cut.

'You had me worried,' Khasar said.

Tsubodai did not smile. He was younger than both the brothers, but they waited patiently for him to speak. He was the great general, the master who could plan any attack on any terrain and somehow snatch victory. With Tsubodai, they knew Ogedai had a chance. Kachiun frowned at the thought.

'You should look to your own safety as well, Tsubodai. You are too valuable to lose.'

Tsubodai sighed. 'To hear such words while I sit by the ger of my khan. Yes, I will be careful. I am an obstacle to the one we all fear. You should be sure that your guards are men you trust with your life, who cannot be bribed or threatened without them coming to you. If a man's wife and children go missing, will you still trust him to watch you as you sleep?'

'That is an ugly thought,' Jebe said, with a wince. 'You truly think we are at that point? On such a day I can hardly believe in knives in every shadow.'

'If Ogedai becomes khan,' Tsubodai went on, 'he could have Chagatai killed, or simply rule well or badly for forty years. Chagatai will not wait, Jebe. He will try to arrange a death, an accident, or he will try to take it by force. I cannot see him sitting idly by while his life and ambition is decided by others. Not the man I know.'