‘Where is the shah?’ he demanded of each one. They had found camels laden with tents of silk and Jebe’s men had discovered a cache of jewels and already gambled or exchanged half of them.

When Genghis asked Tsubodai, the general shook his head thoughtfully.

‘His horsemen are gone, lord khan,’ he replied. ‘I did not see even one.’

Genghis swore, his weariness vanishing.

‘Get the scouts out looking for tracks. I want him hunted down.’

Those scouts who heard jumped back into their saddles and raced away, while Genghis simmered.

‘If he left last night, he has had almost a day to get away. He must not escape! The Arab merchants talk of armies five times the size of this one, more. Have your men join the scouts. Nothing is more important than this, nothing'

Riders went in all directions and it was not long before two men of Jochi’s tuman came racing back. Genghis listened to the report and paled.

‘Tsubodai! Horses travelling east,’ he said.

Tsubodai stiffened.

‘His cities are in the south,’ he said. ‘He is taking a path around us. May I ride to protect the camp, lord?’

Genghis swore under his breath.

‘No. Take your tuman and get after the shah. If he reaches a city and finds fresh reinforcements, we are all dead.’

Jebe was at the khan’s side when he gave the order. He had seen the shah’s army when it was bright and strong. The thought of facing as many again was sickening. He turned to Tsubodai and raised his head.

‘With my lord khan’s permission, I will come with you,’ he said.

Genghis waved a hand and Tsubodai nodded as he dug in his heels. Tsubodai shouted an order to the closest officer, but did not pause as the man raced to gather Tsubodai’s Young Wolves.

As the news spread, Jochi came riding up to his father. He bowed low in the saddle as he reined in.

‘Is the camp in danger?’ he asked.

Genghis turned his pale gaze on the young general, noting the tiger skin draped across his pony. All of them had family there, but he bristled anyway. It had been his order to leave the camp undefended. There had been no other choice.

‘I have sent Jebe and Tsubodai to hunt the shah,’ Genghis replied at last.

‘They are good men, the best you have,’ Jochi replied. His father’s face was cold, but he went on carelessly, thinking of his mother. ‘May I take my tuman and bring the families back here?’

Genghis considered, grudgingly. The camp was less than a day’s ride east of Otrar. He did not like the thought of Jochi announcing the victory to the women and children. No doubt the young man was already thinking of a hero’s welcome. Genghis felt his stomach twist at the thought.

‘I need you at Otrar,’ he said. ‘Give Chagatai the order.’

For an instant, Genghis saw anger flash in Jochi’s eyes. The khan leaned forward in his saddle, his hand dropping to his sword hilt. Even in that, he felt swelling bitterness, as Jochi carried the wolf’s-head sword on his hip. The lapse was quickly masked and Jochi bowed his head and trotted away to speak to his younger brother.

Chagatai was at the centre of a riotous group of young warriors. He did not see Jochi approach at first and was in the middle of laughing at some comment when he stiffened. The men with Chagatai took their lead from him and Jochi walked his pony through their hostile stares.

Neither brother spoke a greeting. Jochi let his hand drop to the tiger skin at his pommel, his fingers toying with the stiff fur. Chagatai waited for him to speak, raising one eyebrow, so that his companions chuckled.

‘You are to take your tuman back to the camp and bring them to the land around Otrar,’ Jochi said, when he tired of the game. Chagatai frowned. He did not want to nursemaid women and children while Otrar trembled for the first sight of them.

‘Whose order is this?’ he replied. ‘Whose authority?’

Jochi controlled his temper at the insolent tone.

‘Genghis bids you go,’ he said, turning his mount to ride away.

‘So you say, but who listens when a rape-born bastard speaks?’

Chagatai spoke knowing he was surrounded by his own men, all waiting for such a barb that they could repeat with relish at the campfires. Jochi stiffened in the saddle. He should have left the grinning fools, but nothing in the world brought him to anger as easily as his younger brother’s blustering arrogance.

‘Perhaps he feels you are a fitting companion for the women after the way you knelt to me, brother,’ he replied. ‘I cannot know his mind.’

With a tight smile, Jochi held his mount to a walk. Even with armed men at his back, he would not give them the satisfaction of seeing him urge his pony to a trot.

He heard the sudden rush of hooves and his hand fell automatically to the wolf’s-head hilt before he snatched it away. He could not draw a blade on Chagatai in front of so many witnesses. It would be the end of him.

Jochi glanced back as unconcernedly as he could. Chagatai was closing the gap between them, with his tail of followers trotting behind. His brother was red-faced with rage and Jochi had barely opened his mouth to speak again when the young man launched himself from the saddle, taking Jochi down hard.

As they hit and rolled, Jochi lost his temper and struck out, his blows thumping uselessly. They came apart and both of them leapt up with murder in their eyes. Even then, old habits were strong and they did not reach for their swords. Chagatai came at Jochi with his fists high and Jochi kicked him as hard as he could between the legs.

Chagatai collapsed in agony, but his fury was so all-consuming that, to Jochi’s amazement, he struggled to rise and staggered into him again. By then, his companions had dismounted and they pulled the two generals apart. Jochi wiped a smear of blood from his nose and spat contemptuously on the ground at Chagatai’s feet. He watched as his brother recovered some semblance of calm and only then did he glance over to Genghis.

The khan was pale with rage and, as his eyes met Jochi’s, he dug in his heels and trotted closer. Not one of the warriors dared look up as they froze in his presence. His temper was legendary in the families and the youngest men were suddenly aware that their own lives might hang on a word or a gesture.

Only Chagatai seemed unaffected. As his father approached, he stepped forward and tried to backhand his brother across the face. Jochi ducked instinctively and was off balance when Genghis kicked him hard between the shoulder blades, sending him sprawling.

Even Chagatai became still at seeing that, though his sneer remained. Genghis dismounted slowly, his fists tight on the reins until he forced them open.

When he turned to his sons, his anger was clear enough to make Chagatai step back. It was not enough. Genghis placed his hand on Chagatai’s chest and pushed him flat to join Jochi on the ground.

‘Are you children still?’ Genghis said. He shook visibly at the young fools who dared to brawl while their men looked on. He wanted to take a stick and beat sense into them, but the last thread of his control held him back. If he thrashed them, they would never again command the respect of his warriors. Sly whispers would follow them the rest of their lives.

Neither Jochi nor Chagatai responded. Finally aware of the danger they were in, they chose to say nothing.

‘How can you command…?’ Genghis stopped before he destroyed them both, his mouth working soundlessly. Kachiun had galloped across the makeshift camp as soon as he heard and his approach allowed the khan to break off his glare.

‘What would you do with young fools like these?’ Genghis demanded of Kachiun. ‘With all the enemies we still face, with our own camp in peril, they fight like boys.’

His eyes pleaded silently with Kachiun to find a punishment that would not be the end for them both. If it had been Jochi alone, he would have ordered his death, but it had been Chagatai he had seen leaping off his horse to roll his brother in the dust.