Yusuf grinned, unabashed.

‘Do not play games, my friend. He will want to hear what I know. Take me to him and I will not mention how you nearly let me die before your walls.’

Ibrahim spluttered in confusion.

‘Truly, he is not in Almashan. Is he coming here? Let me have drinks and food brought for you. Tell me what you know and I will pass it on when the shah arrives.’

The messenger’s smile faded slowly as he understood, replaced by a great weariness.

‘I had hoped he would be here,’ he muttered to himself.

Ibrahim watched as the young man tapped the fingers of one hand on the leather saddlebags, as if the contents had grown too hot to hold comfortably.

‘I must leave,’ Yusuf said suddenly. He bowed to Ibrahim, though the gesture was formal and stiff. ‘My words are for the shah alone and, if he is not in this place, I must travel to the next city. Perhaps they will not make me wait until the very last moment to let me in.’

Ibrahim would have replied, but the noise at the gate ceased as suddenly as it had begun. With a nervous glance at his idiot brother, he raced back up the stone steps to the walls. The other men followed him and together they gazed out.

The Mongols were riding away. Ibrahim breathed in relief and thanked Allah for his city. How many times had the council complained of the cost when he had reinforced and repaired the crumbling walls? He had been right and a thousand times right. The Mongols could not assault his home without their stone-throwers, perhaps not even then. Almashan scorned their swords and bows. Ibrahim watched in delight as the enemy warriors rode clear without looking back.

‘They are clever,’ Yusuf said at his shoulder. ‘It could be that they seek to lull us. I have seen it before. Do not trust them, master.’

Ibrahim’s confidence had grown and he was expansive as he replied.

‘They cannot break our walls, Yusuf. Now, will you take cool drinks in my house? I am curious to know the messages you carry.’

To his frustration, the young man shook his head, his attention still on the Mongol riders.

‘I will not stay here. Not when the shah is close by. He must be told. Greater cities than this one depend on me reaching him.’

Before Ibrahim could reply, the man leaned over the parapet, looking down.

‘Did they kill my horse?’ he asked.

Ibrahim’s brother cleared his throat.

‘They took it,’ he said. Yusuf swore as he went on. ‘I have a good mount, a mare. You could have her.’

‘I will buy her from you,’ Yusuf replied.

Ibrahim’s brother bowed his head, though he was relieved at the offer.

‘She is very strong. For the shah’s man, I will give you an excellent price,’ he said.

Ibrahim could only stand with his fists clenched as his brother sent a man to bring his second-best mare to the gate. The young messenger strode back down the stone steps and Ibrahim was forced to follow with the others. He could not help glancing at the bulging saddlebags once more, silently considering whether the contents would be worth cutting a man’s throat. As the thought formed, Yusuf seemed to sense it and smiled again.

‘There is nothing of value in my bags, master,’ he said. He reached up and tapped his head. ‘My messages are all in here.’

Ibrahim coloured, flustered that the young man had guessed his thoughts. When the mare came, the messenger inspected the animal with the eye of one who knew horses. At last he was satisfied and paid Ibrahim’s brother more than he had asked, honouring him. Sourly, Ibrahim watched the young man check the belly strap and reins. Above their heads, the guards called that the way was clear.

‘I would pay well to hear those messages,’ Ibrahim said suddenly. To his surprise, the messenger hesitated. ‘In gold,’ Ibrahim went on, sensing the first weakness.

‘Very well, master,’ Yusuf replied. ‘I need funds to continue my search for the shah. But it must be quick.’

As Ibrahim fought to hide his pleasure, the messenger passed the reins to a guard and followed him to the nearest house. The family within made no protest when Ibrahim told them to leave. In just moments, he was alone with the messenger, almost quivering to hear the news.

‘The gold you promised?’ Yusuf said softly.

In his excitement, Ibrahim did not hesitate. He took a full pouch from under his robe, still warm and damp from his skin. The younger man hefted it, glancing at the contents with a wry smile before making it disappear.

‘This is for you alone, master,’ Yusuf said, his voice almost a whisper. ‘My poverty forces me to speak, but it is not for all ears.’

‘Tell me,’ Ibrahim urged. ‘It will go no further.’

‘Bukhara has fallen, but the garrison at Samarkand achieved a great victory. The khan’s army was shattered in the field. For this year alone, they are weak. If the shah returns to lead his loyal cities, he will have all their heads. If he comes, master. That is why I must find him quickly.’

‘Allah be praised,’ Ibrahim whispered. ‘I see now why you cannot delay.’

The messenger pressed his hands to his forehead, lips and heart in the ancient gesture.

‘I am the shah’s servant in this, master. The blessing of Allah on you and your honourable house. Now I must ride.’

Ibrahim moved quickly then, striding with more confidence back to the gate. He felt the eyes of all his men on him and even his foolish brother stared as if he might discern what the messages had been.

Once more the small door in the gate opened to let in sunlight and air to that stifling place under the walls. The messenger bowed to Ibrahim and then led his mount through the gap. The door was shut and barred behind him and he dug in his heels, riding hard across the dusty ground.

It was sunset before Yusuf caught up with the tuman of Tsubodai and Jebe. He rode into the makeshift camp they had made, acknowledging the calls of warriors. He was nineteen years old and more than pleased with himself. Even Tsubodai smiled at the young Arab’s confidence as he dismounted with a flourish and bowed before the two generals.

‘Is the shah there?’ Tsubodai asked.

Yusuf shook his head. ‘They would have told me, general.’

Tsubodai pursed his lips in annoyance. The shah and his sons were like wraiths. The Mongols had chased the man and his guards right through to the end of summer and still he evaded them. Tsubodai had placed his hopes on him going to ground in the city on the river, its walls too high for an assault.

‘He is a slippery fish, that old man,’ Jebe said. ‘But we will catch him in the end. He cannot get south past our lines without someone seeing him, even with the men he has left.’

Tsubodai grunted.

‘I wish I could be so certain. He had the wit to send his men on a false trail. We almost lost him then and it is much harder to track just a few.’ He rubbed his arm where one of the shah’s guards had surprised him. It had been a well-laid ambush, but the guards had been vastly outnumbered. Though it took time, Tsubodai and Jebe had slaughtered them to the last man. They had checked the face of every dead Arab, but they had all been young and strong. Tsubodai bit his lip at the memory. ‘He could hide himself in a single cave and scrub out his tracks. We could have ridden past him already.’

‘They know nothing in the city, general,’ Yusuf said. ‘The shah did not stop for supplies anywhere near here. The slavers would have heard and told me.’ He had expected to be congratulated on the success of his subterfuge, though it had been Tsubodai’s idea. Instead, the two generals were back to their discussions as if it had been nothing. He did not mention the pouch of gold he had won with a few lies. They had noticed the new mare he had brought back and would consider that enough of a reward for his work. The Mongol generals did not need to know everything.