‘Will you leave this city, master?’ he asked, his voice slightly choked by the pressure of Tsubodai’s blade.

Genghis raised his eyebrows, surprised at the courage he saw. Or madness, or fear, though who could inspire more fear than a sword at the throat, he did not know.

‘I will leave today, boy, yes. Now speak.’

Yusuf swallowed drily.

‘The Assassins bear such a mark, such a word, master. That is truly all I know.’

Genghis nodded slowly.

‘Then they will be easy to find. Put your sword away, Tsubodai. We need this one.’

‘I have found him useful, lord,’ Tsubodai replied. ‘With your permission, I will send a runner to the general with this news. He will want to have all his staff checked for the mark, perhaps everyone in the city.’ As the thought formed, he turned and grabbed Yusuf, yanking his robe aside before he could react. The skin was bare and Yusuf glared at the general as he rearranged himself.

‘That would be wise,’ Genghis said. He looked around him at the dead bodies, already attracting flies. Samarkand was no longer his concern.

‘Hang my guards before you join me, Tsubodai. They failed today.’

Ignoring the pain from his hip, he remounted and rode out to the tumans.

The movement of the khan’s ger rocking on its cart was a strange sensation for Yusuf Alghani. The young Bedouin had seen many astonishing things since offering his services to the Mongols. As the day wore on and the tumans moved out with the families, he had expected to be summoned once more to face the khan. Yusuf had watched in interest as every Arab man and woman was checked for the mark of serenity. There were a surprising number of dark-skinned faces in the camp once Yusuf had noticed. In the years since the Mongols had crossed to Khwarezm, they had picked up almost a thousand Arabs in their wake, both young and old. They worked as interpreters for the most part, though some practised medicine and others joined the Chin as engineers and craftsmen working for the khan. Genghis didn’t seem to care when they broke off their labours to roll out prayer mats, though Yusuf was not sure whether it was from respect or indifference. He suspected the latter, as the camp contained Buddhists and Nestorian Christians as well as Moslems, with far more of the infidel faiths than true believers.

Yusuf waited for the khan to speak as the man finished a meal. He had even allowed Moslem butchers to kill goats and sheep in the way they desired and the Mongols did not seem to care how they ate or lived as long as they obeyed. Yusuf could not understand the man who sat across from him, idly picking something from his teeth with a splinter. When the word had come to attend the khan, Tsubodai had taken him by the arm and said to do whatever he was told.

Yusuf hardly needed the warning. This was the man who had slaughtered his people in tens of thousands, more. Yet the dead shah had done the same in his wars and persecutions. Yusuf accepted such things. As long as he survived, he did not care whether the khan succeeded or was left for the crows.

Genghis put aside his plate, but kept a long knife ready on his lap. The warning was not wasted on the young man watching him.

‘You seemed nervous in the market,’ Genghis said. ‘Do they have such a reach then, these Assassins?’

Yusuf took a deep breath. He was still uncomfortable even talking about them, but if he was not safe surrounded by tumans of warriors, then he was already dead.

‘I have heard it said they can reach a man anywhere, master. When they are betrayed, they bring terrible vengeance on those who defied them, relatives, friends, whole villages even.’

Genghis smiled slightly.

‘I have done the same,’ he said. ‘Fear can hold men in chains who would fight to the death otherwise. Tell me about them.’

‘I do not know where they come from,’ Yusuf said quickly. ‘No one knows that.’

‘Someone must,’ Genghis interrupted, his eyes growing cold, ‘or they could not accept the payments for death.’

Yusuf nodded nervously. ‘That is true, master, but they protect their secrets and I am not among those who know. All I have heard are rumours and legends.’

Genghis did not speak and he hurried on, wanting to find something that would satisfy this old devil who played with a knife.

‘They are said to be ruled by the Old Man of the Mountains, master. I believe it is a title more than a name, as it has been the same for many generations. They train young men to kill and send them out in exchange for vast sums of gold. They do not ever stop until the life is taken.’

‘They were stopped this morning,’ Genghis said.

Yusuf hesitated before answering.

‘There will be others, master, always more until the contract is complete.’

‘Do they all carry this mark on their skin?’ Genghis asked. He thought it would not be too hard to guard his family from men who identified themselves in such a way. To his disappointment, Yusuf shook his head.

‘I thought that was part of the legend, master, until I saw it in the market. It is a sin against God for them to mark their bodies in such a way. I was surprised to see it at all. I do not believe they will all carry the mark, especially now you have been seen to discover it. The ones who come now will be young men, their skin untouched.’

‘Like you,’ Genghis said softly.

Yusuf forced a laugh, though it sounded hollow.

‘I have been loyal, master. Ask your generals Tsubodai and Jebe.’ He struck his chest. ‘My allegiance is only to you.’

Genghis snorted at the lie. What else would the young man say, even if he were an Assassin? The notion that any one of the Arabs in his camp might be a killer was worrying. He had wives and young children, as had his brothers. He could guard himself against armies, but not enemies who came in the night and gave their lives to take his.

Genghis recalled the Chin assassin who had come out of Yenking to murder him in his ger. Luck had saved him that night and then only barely. The poisoned knife had caused him more pain and weakness than he had ever known. Even the thought of it brought sweat to his brow as he glared at the young Arab. He considered having Yusuf taken out, away from the women and children. His men would have him telling them anything they wanted to hear in no time at all.

Yusuf squirmed under the fierce gaze, his senses screaming that he was in terrible danger. It was the effort of a lifetime not to dart from the ger and run for his horse. Only the fact that the Mongols could ride down anyone alive held him in place. The cart lurched as the wheels passed over a rut in the ground and Yusuf almost cried out.

‘I will ask, master. I promise you. If anyone who knows how to find them crosses my path, I will send them to you.’ Anything to make him more valuable to the khan alive, he thought to himself. He did not care if the Mongols destroyed the Assassins, only that Yusuf Alghani was standing when the killing stopped. They were Ismailis, after all, a Shia sect and not even true Moslems. He had no loyalty to them.

Genghis grunted, toying with the knife in his hands.

‘Very well, Yusuf. Do that and report anything you hear to me. I will search in different ways.’

The young man heard the dismissal in his words and left quickly. Alone, Genghis cursed under his breath. He threw the knife so that it struck the central post of the ger and stayed there, quivering. He could destroy cities that sat where he could see them. He could break armies and nations, both. The thought of insane killers lunging for him in the night made him want to lash out. How could he protect his family against such people? How could he keep Ogedai safe to inherit? There was only one way. Genghis reached for the knife and worked it free. He would have to find them and burn them out, wherever they hid. If they moved as his own people did, he would find them. If they had a home, he would destroy it. The conquest of cities would have to wait.