‘You brought me to this dry land,’ Genghis told the shuddering figure. ‘I offered you peace and trade and you sent me the heads of my men. Now I have given you your precious silver to hold.’

Inalchuk said nothing, though his lips worked soundlessly.

‘Do you have no words to thank me?’ Genghis went on. ‘Is your throat too dry? Accept this drink from me to slake your thirst. Then you will know a small echo of the pain you have caused.’

The interpreter was silent in horror, but Inalchuk was past hearing. The khan did not bother to watch as the forge men brought up their pot and poured the rest of the metal over the governor’s face. His oiled beard ignited and the open mouth filled, but Genghis only stared at the people on the walls. Many of them turned away, understanding at last that death would come for them.

‘The catapults are finished, Khasar,’ Genghis said, still staring up at the city. ‘You will begin breaking the walls tomorrow at dawn. I want each stone removed from every other. Otrar will not be rebuilt when we have gone. This city will be swept from the face of the world, with every living thing in it.’

Khasar shared the depths of his brother’s hatred. He bowed his head.

‘Your will, my lord khan.’

The Old Man listened at a tiny grille set high in the wall of the cell. He could see only bare outlines in the gloom, but he heard the sounds of a young body stirring as it rose from drugged sleep. He was patient as he waited. How many times had he guided a boy through the ritual of awakening? He had shown the garden to his new recruit, with its glory enhanced by the drug in wine sweetened almost to syrup. He had shown him paradise and now, in the darkness, he would see hell.

The Old Man smiled to himself as he heard a voice cry out below in horror. He could imagine the shock and confusion, recalling how he himself had felt so many years before. The smell of dead flesh was strong in that little cell, the bodies greasy with loose flesh as they lay over the young warrior. The Old Man heard him whisper and sob as he struggled with the limp limbs covering him. It would seem as if only moments had passed since he sat in a place so beautiful that it was almost painful. The Old Man had perfected the garden and chosen the women well, down to the last detail. They were exquisite creatures and the drug had inflamed the young man so that every light touch on his skin had driven him almost to madness. Then he had closed his eyes for an instant and woken with the stinking dead.

The Old Man strained his eyes to see into the gloom. He could see flailing movement as the boy cast around him. He would feel soft matter under his hands in the darkness, perhaps feel the movement of maggots in the meat. The boy moaned and the old man heard him vomit. The stench was appalling and the Old Man pressed a pouch of rose petals to his own nose as he waited. The moment was always delicate, but he was a master of his art.

The boy was naked in that place of the slippery dead. The Old Man saw him plucking at shreds of glistening skin where they had clung to his own. His mind would be fragile, his heart racing to the point of death. The Old Man thought only the very young could survive such an experience, but even they were haunted by it ever after.

The boy yelled suddenly, his attention caught by a shifting mass of rotting flesh. The Old Man smiled at his terrified imaginings and readied the shuttered lamp at his feet, where no stray glow could spoil the lesson. Below him, the boy prayed to Allah to deliver him from his stinking pit of hell.

The Old Man threw open the door to the cell, his lamp shattering the gloom, so that the boy was blinded and fell back with hands over his eyes. To the Old Man’s pleasure, he heard the spatter of hot urine as the boy’s bladder gave way. He had judged the moment well. Tears streamed below the clasped hands.

‘I have shown you paradise,’ the Old Man said. ‘And I have shown you hell. Shall I leave you here for a thousand lifetimes, or shall I take you back to the world? Which one awaits you depends on how well you follow me. On your soul, speak truly. Will you dedicate your life to me to spend as I see fit?’

The boy was fifteen years old. As he knelt and wept, the last traces of sticky hashish faded from his young body, leaving him shaking and weak.

‘Please! Anything you ask! I am yours,’ he said, sobbing. Still he did not dare open his eyes, in case he found the vision gone and was left alone once more.

The Old Man pressed a cup to his lips and let him smell the resin that was said to give courage. The boy gulped at it, the purple wine running down his bare chest and arms. The Old Man grunted in satisfaction as the boy slumped back, his senses spinning away.

When the boy awoke, he lay on clean sheets in a bare stone room, somewhere in the fastness that was the Old Man’s sanctuary from the world. Alone, he wept at what he had seen, unaware that he was still observed. As he swung his legs over and tried to rise, he was filled with determination never to see the demons of the dead room again. He shuddered to remember the way the bodies had moved and stared at him, each memory more vivid and terrifying than the last. He thought he would have gone insane if the garden had not remained also in his mind. Its peace had protected him, even in hell.

The wooden door to the room opened and the boy took a deep breath as he stood before the man of power who had brought him out of that place. The Old Man was short and burly, his eyes fierce in a face as dark as mahogany. His beard was oiled and perfect, but his clothes were simple as always, suited to one who refused all the tawdry trappings of wealth. The boy threw himself full length on the cool stone, prostrating himself for his deliverance.

‘You understand at last,’ the Old Man said softly. ‘I have taken you by the hand and shown you both glory and failure. Which will you choose when the time comes?’

‘I will choose glory, master,’ he said, shaking.

‘Your life is just a bird’s flight through a lit room. You pass from infinite darkness into endless night, with only a short time in between. The room does not matter. Your life does not matter, only how you prepare for the next.’

‘I understand,’ the boy said. He could feel the oily touch of dead limbs on his skin even then and he shuddered.

‘Pity those who do not know what comes after death. You can stand strong among them, for you have seen both heaven and hell and you will not falter.’ The leader of the Assassins raised the boy to his feet with a gentle hand.

‘Now you may join your brothers. Men like you, who have been allowed to press their eye to a crack in the walls of reality. You will not fail them, or me, when you bring a perfect death to the feet of Allah.’

‘I will not, master,’ the boy replied, more certain than he had ever been in his young life. ‘Tell me whom I must kill. I will not fail.’

The Old Man smiled, always touched by the earnest faith of the young warriors he sent out into the world. He had been one of them once, and when the nights were dark and cold, he still sometimes ached for the garden he had been shown. When death took him at last, he could only hope the real thing was as wonderful as the one he had created. Let there be hashish resin in paradise, he thought. Let him be as young and lithe as the boy before him.

‘You will travel with your brothers to the camp of the Mongol khan, he who calls himself Genghis.’

‘Amongst the infidel, master?’ the boy stammered, already feeling unclean.

‘Even so. Your faith will keep you strong. For this and only this you have trained with us for five years. You have been chosen for your skill with languages. You may serve Allah well with his gift.’ The Old Man rested a hand on the boy’s shoulder, his palm seeming to radiate heat. ‘Get close to the khan and, when the moment is right, tear his life from him with a single thrust to the heart. Do you understand the price of failure?’