‘What if we are attacked?’ Chakahai asked.

Borte winced and shook her head.

‘How many times have I been asked that since the orders came?’ she said. She saw the genuine fear in the Xi Xia princess’s eyes and softened her tone. The woman had been given to Genghis as a gift by her defeated father. She had seen chaos in her time and knew the terror that came with it.

‘Do you think we will be defenceless, sister?’ Borte said.

Chakahai too had looked away, but the term of friendship brought her gaze snapping back.

‘Are we not?’ she demanded. ‘What can women and children do against soldiers, if they come?’

Borte sighed.

‘You were not raised in the tribes, Chakahai. If we are attacked, the women will take up knives and fight. Crippled warriors will mount as best they can and attack. Boys will use their bows. We have horses and weapons enough to hurt anyone who troubles us.’

Chakahai stared in silence, her heart pounding. How could her husband have left her undefended? She knew why Borte spoke in such a way. Panic would destroy the camp before they even sighted an enemy. Families would be torn between the safety of numbers and the fact that the camp itself would draw danger to it. Left alone to protect their children, many wives and mothers would be considering leaving in the night to find a safe place in the hills. To a mother of young children, the idea was tempting, but Chakahai resisted. Like Borte, she was the khan’s wife. The others would look to them for leadership. Of all the women left behind, they could not run.

Borte seemed to be waiting for a response and Chakahai thought carefully before replying. The children would be frightened as they saw the last warriors leave. They would need to see confidence, though it was all false.

‘Is it too late for me to learn the bow, sister?’ Chakahai said.

Borte smiled.

‘With those bony, narrow shoulders? It is. But find yourself a good knife.’

Chakahai nodded, though uncertainty swept through her.

‘I have never killed a man before, Borte.’

‘Perhaps you will not have the chance. The knife is to cut and shape straw warriors to put on the saddles of spare horses. In poor light, an enemy will not see our men have gone.’

Borte raised her eyes from her worries and the two women shared a glance before each one turned away, satisfied. There could be no true friendship between them, but neither had found a weakness in the other and both took comfort from that.

As the sun reached its highest point, Khasar looked back at the camp he had been told to abandon. It was as busy as an ants’ nest as women and children scurried between the gers. Even without the tumans, it was a vast assembly, more than a hundred thousand people and gers by a small river. Around them, herds grazed, oblivious. Everything they had looted from the Chin was there, from jade to gold and ancient weapons. Temuge and Kokchu had their collection of manuscripts and books. Khasar bit his lip at the thought of the shah’s soldiers finding such a prize undefended. Perhaps a thousand elderly or crippled warriors would remain, but he did not hold out hope that those who had lost arms and legs would stop a determined enemy. If they came, the gers would burn, but his brother had called him and he would not disobey. He had three wives and eleven young children somewhere in the maze of gers and he regretted not taking the time to speak to them before gathering his men.

It was done. The sun was high and he had been called. Khasar looked at his second in command, Samuka. The man was caught between pride at his promotion to lead a tuman and shame at abandoning the camp. Khasar clicked his tongue to catch the other man’s attention, then raised his arm and let it fall. His men kicked in their heels and rode with him, leaving everything they valued behind.

Jochi and Jebe rode together at the head of the tumans. Jochi’s mood was light as they wound their way through valleys back into the west. He had lost almost a thousand men. Some had fallen in the wild charge across the face of the ridge, while more had been cut down or fallen from sheer exhaustion in the long ride that none of them would ever forget. Most of those had been from his Chin soldiers, but those who survived rode with their heads high, knowing they had earned the right to follow their general. Jebe had lost as many, but they were men he had known for years under Arslan. They had died well, but would still be denied the sky funerals, where bodies were taken to the highest peaks to feed hawks and birds of prey. Both generals knew there was no time to honour the dead. Genghis’ brother-in-law Palchuk had been among the bodies, found with a great gash across his face from an Arab sword. Jebe did not know how Genghis would respond to the news and spent two days resting by the lake in grim silence.

Jebe and Jochi were painfully aware of the threat to the khan, but the horses were spent. They had been forced to let the animals recover their strength before remounting. Even then, it was too early. Many were still lame and it hurt the senior men to order the ruined ones killed and the meat distributed. Dozens of warriors carried a rack of ribs or a leg across their saddles, while others rode Arab horses in little better condition. For men who saw horses as the only true spoils of war, the battle in the pass had been a triumph worth telling round the fires for a generation. With each warrior, two or three of the Arab mounts ran alongside. Many were lame and broken-winded, but their strength could be used and the Mongols could not bear to leave them behind.

Eighteen thousand men rode with the generals as they turned away from the main valley and took a more tortuous route. As tempting as it was to ride in their own steps, the shah could well have left an ambushing force somewhere ahead. The men needed time to recover before facing an enemy once more.

Water at least was plentiful. Many of the men had drunk until their bellies were swollen. When they were being chased, they had emptied their bladders as the need came, letting the warm water cut through the coating of dust on their mounts. On the way back, they had food in them. The speed had been slowed by dozens at a time dismounting quickly and squatting on the ground before wiping themselves with rags and leaping back on. They were stinking, filthy and thin, but hardened by the land they had ridden for so long.

It was Jochi who saw the scouts riding back from a ridge ahead. In Jebe, he had found a man who understood the need to know terrain as well as Tsubodai and they were always surrounded by a ring of riders many miles out. Jochi whistled to catch Jebe’s attention, but the other general had also seen and merely raised his eyebrows in surmise.

‘Did I not send two men that way?’ Jochi called. Three were returning, and even from a distance, they could see the other rider was a scout like their own, without armour or anything but a sword to slow him down. Some even rode without that weapon, depending on speed alone.

Without a signal, the young generals kicked their mounts forward of the line, hungry for information.

The scout was not from their tumans, though he looked almost as weary and dusty as their own men. Jochi and Jebe looked on as the young man dismounted and bowed, holding his reins in his hands. Jebe raised a hand and the warriors came to a halt. At first, the scout hesitated in the presence of two generals, unsure whom to address first. Jochi’s impatience broke the silence.

‘You have found us,’ he said. ‘Report.’

The scout bowed again, overwhelmed to be speaking to a son of the khan.

‘I was about to turn back when I saw the dust of your horses, general. Tsubodai sent me out. The shah is in the field with a great army.’

If the scout had expected any excitement at this news, he was disappointed.