Jelme frowned and let his fingers drop to a long shaft that had struck him in the shoulder. It had passed through armour to cut his flesh just below the skin. Jelme worked furiously at it, trying to pull it free. Tsubodai came close and took the shaft, snapping it quickly and throwing the pieces down.

‘Thank you,’ Jelme said. ‘Is it our missing generals?’

‘Who else has two tumans in this place?’ Tsubodai replied. ‘We could have used them before, but I shall send them around the passes to attack the shah as he comes out.’

‘No,’ Jelme replied. ‘You and I can do that well enough. Let these latecomers take our leavings and follow the shah into the pass. I am still fresh, general. I will fight again today.’

Tsubodai grinned and clapped Jelme on the shoulder. He sent two scouts back to carry orders to Jebe and Jochi before peeling off and calling his men after him. The closest pass was little more than a mile away.

In just moments, the attack on the rear had ceased and the last of the shah’s bloody soldiers passed between the hills. As shadow crossed their faces at last, they looked fearfully back at the wild horsemen who rode so swiftly towards somewhere else. No one cheered to have survived it. They were filled with dark foreboding and as they looked behind at the swathe of dead they had left, another army rode closer and closer, ready to begin the killing again.

Tsubodai forced his mount over broken ground, heading up into the hills. The second pass was a narrow trail and the shah might well have discounted it for so many men. Still, it served a rank of ten across, and as he climbed, Tsubodai looked at the farmlands below, seeing a wavering red slash marking the path of the battle, quickly drying to brown. Over it came the tumans of Jochi and Jebe and, even from that distance, Tsubodai could see they were riding slowly. He saw the tiny figures of his scouts reach them and the pace picked up.

Tsubodai’s view was blocked after that and he did not see them follow the shah into the pass. Kachiun would be out of arrows and still the army was too large for the forces of Genghis at Otrar. Yet Tsubodai was pleased with the killing. He had shown the strength of the columns on their own and the best way to act against a slow enemy. He looked ahead to where Jelme rode, urging on his men. Tsubodai smiled at the older man’s enthusiasm and energy, still undimmed. Every warrior there knew that they might have another chance to attack if they could get through the hills before the shah reached open ground. There would be no place for stinging wasps then, Tsubodai realised. With the right timing, they would hit the shah’s right flank with the best part of twenty thousand men. Most of their arrows had gone. Shields and swords would have to finish what they had begun.

In the morning sun, Genghis turned quickly enough to make Khasar jump. When he saw it was his younger brother, the khan’s face grew a fraction less terrible, but the visible strain remained. Genghis had lived on anger and frustration for two days, while his men fought and died beyond the southern hills. If the walls of Otrar had been a little less thick, he would have had the catapults working all that time. Instead, it would have been a pointless gesture and he had waited. The city was not as important as surviving the shah’s army, but inaction had worn his temper to bare bones.

‘Give me good news,’ Genghis snapped.

Khasar hesitated and Genghis scowled as he saw it.

‘Then give me whatever you have,’ he said.

‘The scouts report a battle before the pass. The generals have thinned the shah’s men as you ordered, but the army is still mostly intact. Kachiun is ready with archers on the high slopes. They will kill many, but unless the army breaks and runs, the shah will come through. You knew it would be so, brother.’

He watched as Genghis clenched his left fist hard enough to make the arm shake.

‘Tell me how to stop twenty thousand warriors falling on us from behind and I will stand in the shah’s path as he comes out,’ Genghis said.

Khasar looked away at the city that mocked their preparations. With the camp stripped of warriors, five full tumans waited for orders and Genghis chafed at every wasted moment. He did not underestimate the risk he had taken. As well as his wives, his sons Ogedai and Tolui had been left without protection as he tried to wring every advantage from the forces available to him. As the sun had risen on a second day, only Khasar had dared speak to his brother and he could offer no solution.

Khasar knew as well as his brother that if the shah made it through the hills with his army, the garrison at Otrar would attack as soon as they saw his banners. The tumans would be crushed. Khasar knew he did not have the brilliance of Tsubodai or even the wits of Kachiun, but he could see only one order to give. They could not hold Otrar. All they could do was retreat, drawing all the generals with them. Still, he waited for Genghis.

The black smoke of the burning outer city had dwindled to nothing over the previous days. The air was clean and hot as Genghis looked over his army. The city was silent as they waited for deliverance.

‘There will be other years, brother,’ Khasar said, his patience dissolving. ‘Other battles.’

‘You would have me retreat, Khasar?’ Genghis turned to his brother once more.

Khasar shrugged.

‘Better than being killed. If you take the tumans ten miles north, this shah will join the garrison at Otrar and then at least we will face one army, with no one to attack the rear.’

Genghis snorted in disdain for the idea.

‘Miles of plains and mountains that they know better than we do. They would batter us all the way home and even my generals cannot stop so many. Yet if I can reach this pass, the shah will not be able to manoeuvre. Even now, it would be hard to reach him before the sun sets, brother. Time is killing us.’

Genghis fell silent suddenly, as a thought struck him.

‘The man who was your second, Samuka. Is he loyal?’

Khasar narrowed his eyes, wondering what Genghis was thinking.

‘Of course,’ he replied.

Genghis nodded sharply, making a decision.

‘Give him five thousand men and have him hold this place until I return. He does not have to win the battle, just prevent them from entering the field. Tell him I need time and that he must win it for me.’

Khasar did not reply at first. Chagatai’s tuman was closer to the city than Samuka’s men, but Khasar knew Genghis would not send his son to certain death, as he seemed willing to do with Samuka.

‘Very well, brother. I will tell him,’ he said.

Genghis was already mounting his horse and turning it to take his place at the head of the army. Khasar rode back to the ranks, cutting across at a gallop to reach Samuka.

He found his old second in command standing with Ho Sa, discussing the riding order. Their faces lit up as they saw Khasar and his heart sank at what he had to say. With a gesture, Khasar drew them apart from the other officers and spoke in a low voice.

‘My lord Genghis orders you to stay behind, Samuka. Take five thousand of the best archers and hold the city until we return.’

Ho Sa stiffened as if he had been struck. Samuka’s dark eyes searched Khasar’s for a moment. All three men knew it was a death sentence. The garrison would cut them to pieces in their desperation to get out of the city.

‘They will do their best to break through,’ Khasar went on. ‘It will be bloody work.’

Samuka nodded, already resigned. Five thousand men would not be enough to hold two gates. As a thought struck him, he glanced to Ho Sa.

‘I do not need this one, general. Let him go with you.’ Samuka smiled tiredly. ‘He is useless anyway and I will not need him here.’