He fell then, thinking he must have slipped in someone's blood. Huran saw the iron bar spring out. The room seemed lighter somehow, as if the wolf's dawn had come at last. Huran gasped as someone trod on his outstretched hand, breaking bones, but the pain was fleeting. He was dead before Tsubodai had turned at bay to face the men who roared into that room, wild with release and hungry to do their work. The stalemate at the gates had become Chagatai's triumph. He had enjoyed his uncles' expressions as Jelme brought a tuman up to his side. Tolui's tuman had matched him on the other side, its men straining at the leash with knowledge that their lord and his family were trapped in the city, perhaps already dead.

One by one, all the generals of the nation brought their men to the city walls, stretching away into the darkness. More than a hundred thousand warriors stood ready to fight if they had to, but there was no battle heat in them while their commanders sat and stared coldly at each other.

Jochi's son Batu had declared for Kachiun and Khasar. He was barely seventeen years old, but his thousand men followed his lead and he rode with his head high. He was a prince of the nation despite his youth and his father's fate. Ogedai had seen to that, promoting him as Genghis would never have done. Even so, Batu had chosen to stand against the most powerful man in the tribes. Kachiun sent a runner to him to thank him for the gesture.

In Tsubodai's absence, Kachiun's mind was running faster than his peaceful look suggested. He thought Jelme was still loyal to Ogedai, though Chagatai had accepted him. It was no small thing to have perhaps a sixth of an enemy's army ready to turn against him at a crucial point. Yet the sides were too evenly matched. Kachiun had a vision of the army falling in on itself until there were just hundreds left alive, then dozens, then just one or two. What then of the great dream Genghis had given them? He at least would never have countenanced such a waste of life and strength – not among their own people.

The wolf dawn showed in the east, the faint greying of the land before the sun rose above the horizon. The light spread over the host gathered by Karakorum, illuminating the faces of the generals and their men so that there was no need for torches. Even then, they did not move and Chagatai sat and chatted with his bondsmen, barking out laughter as he enjoyed the new day and everything it would bring.

When the first thin line of gold appeared in the east, Chagatai's second in command clapped him on the back and the men around him cheered. The sound was quickly taken up by the other tumans on his side. Those with Khasar and Kachiun sat in sullen and thoughtful silence. It did not take a mind like Tsubodai's to interpret Chagatai's pleasure. Kachiun watched with narrow eyes as Chagatai's men began to dismount, so that they could kneel to him as khan. He pursed his mouth in rising fury. He had to stop it, before it became a wave across all the tumans and Chagatai was made khan on a wave of oaths, before Ogedai's fate was even known.

Kachiun moved his horse forward, holding up a hand to the men who would have followed him. Khasar too came forward, so that they rode alone through the ranks of men towards Chagatai.

Their nephew was ready from the first step they took in his direction, as he had been all night. Chagatai drew his sword in unmistakable threat, but he still smiled as he gestured to his bondsmen to let them through. The rising sun lit the host of warriors. Their armour glimmered like a sea of iron fish, scaled and dangerous.

'It is a new day, Chagatai,' Kachiun said. 'I will see your brother Ogedai now. You will open the city.'

Chagatai glanced once more at the dawn and nodded to himself.

'I have done my duty, uncle. I have protected his city from those who might have run riot inside on the eve of the oath-taking. Come, ride with me to my brother's palace. I must be certain he is safe.' He grinned as he spoke the last words and Kachiun looked away rather than see. He watched the gates begin to open, laying the empty streets of Karakorum bare before them. Tsubodai was no longer a young man, but he wore full armour and he had been a soldier longer than most of the attackers had been alive. As they came in a welter of limbs and blades, he darted six steps away from the door. Without warning, he spun and lunged, taking the closest man to him through the throat. Two more brought their blades down in reaction, hacking wildly at his scaled armour and leaving bright marks in the tarnish. Tsubodai's mind was perfectly clear, faster than their movements. He had expected to retreat immediately, but the hurried blows showed him their weariness and desperation. He struck again, reversing his blade for a pull stroke that jerked the steel across a man's forehead, opening a flap so that he was blinded with blood. It was a mistake. Two men grabbed hold of Tsubodai's right arm. Another kicked his legs away and he fell with a crash.

On the ground, Tsubodai exploded into a frenzy. He lashed out in all directions, using his armour as a weapon and always moving, making himself harder to hit. The metal plates on his leg opened a gash in someone's thigh and then he heard roaring and still more men poured into the room, more than it could hold. Tsubodai struggled on desperately, knowing he had lost and Ogedai had lost. Chagatai would be khan. He tasted his own blood in the back of his throat, as bitter as his rage.

At the barricade, Ogedai and Tolui waited shoulder to shoulder. Sorhatani stood with the bow, unable to shoot while Tsubodai still lived. When he went down, she sent two shafts between her husband and his brother. Her arms were nowhere near strong enough for a full draw, but one of the arrows checked a man in his rush while the other ricocheted away into the ceiling. Ogedai stepped in front of her as she struggled to notch a third with shaking fingers. The view beyond the barricade was blocked with grasping hands and blades and bloody faces. She did not understand what was happening at first. She flinched at a roar as more men came into the outer room. Some of those struggling with Ogedai and Tolui turned at the sound and then they were yanked back. Sorhatani saw a sword appear through the throat of a man facing her, as if he had grown a long and bloody tongue. He fell jerking and the view was suddenly clear.

Ogedai and Tolui panted like dogs in the sun. In the other room, a group of armoured men were finishing off the attackers with quick, efficient blows.

Jebe stood there, and at first he ignored the survivors, even Ogedai. He had seen Tsubodai on the ground and knelt at his side just as the general struggled to his knees. Tsubodai was shaking his head; dazed and gashed, but alive.

Jebe rose and saluted Ogedai with his sword.

'I am pleased to see you well, my lord,' he said, smiling.

'How are you here?' Ogedai snapped, his blood still surging with anger and fear.

'Your uncles sent me, lord, with forty bondsmen. We had to kill a lot of men to reach you.'

Tolui clapped his brother on the back in delight before he turned and embraced Sorhatani. Kublai and Mongke punched each other on the shoulders and mock-scuffled until Kublai was in Mongke's headlock.

'Tsubodai? General?' Ogedai said.

He watched as Tsubodai's glazed eyes cleared. A warrior put out his hand to steady the general and Tsubodai batted it away irritably, still shaken by how close he had come to death at the feet of the attackers. When Tsubodai got to his feet, Jebe turned to him, as if reporting.

'The Broken Lance closed the gates of the city. All the tumans are outside, on the plain. It may be war yet.'

'How then did you get inside my city?' Ogedai demanded. He looked for Huran and remembered with a pang of loss that the man had given his life at the first door.