The shattered mosaic floor on the far side of the courtyard wobbled and blurred in the blistering heat. He had woken at dawn and been praying ever since. He had not eaten today nor had he drunk. He would wait until the craving had passed, then allow himself to do both when it became a choice, not a lost battle in his long war against the base needs of the body. There was grit under his knees. The pain was mortality made manifest. It demonstrated the shape and strength of that which he must rise above.

For eighteen years he had lived inside the ruins of this little Roman fort in the desert past Krokodilopolis, devoting himself entirely to worship and contemplation, wearing rags and depending entirely on the charity of nearby villagers for sustenance. The original roof was long gone, but the walls, though partially collapsed in places, were still high enough to hide the surrounding landscape so that he could see nothing beyond the fort but sky. There was little protection from the sun during the day and no protection from the cold at night. The worst of the wind was kept out at least. He stored his food and water in the slim wedges of shade inside the perimeter of the compound and relieved himself in the far corner where scavenging insects consumed his excrement before it was dry.

The devil had tempted him forcefully and relentlessly. A rain of gold coins lay on the ground for days, finally evaporating when he refused to touch them. Every so often a great trestle table of pies and tarts and wines would appear in the centre of the courtyard. The devil himself would sit in his ear for days on end talking softly about all the pleasurable and profitable things he could do with his life. Demonic women had appeared in the small hours and invited him to join them in a range of sexual acts that beggared belief. Angered by his persistent refusal to weaken, the devil had sent a swarm of tiny, blood-red demons with spines like needles and razor teeth who tore his flesh to shreds, leaving his body permanently peppered and striped with scars.

A fat, brown scorpion sidled on to a rock beside him, its tail vibrating. It looked like a real scorpion but it was hard to be certain about such things, and he had to be on his guard. In the corner of his eye he could see a vulture turning overhead. One had landed on him a few months ago, puncturing his left shoulder with its talons and hacking out a chunk of his scalp with its beak. He had flinched and cried out and the bird had flown sullenly away.

The scorpion descended from its rock and scuttled off.

He could hear distant voices, a faint whoop and the slap of leather on powdery stone. He would not turn immediately. He would not allow himself to be steered by mere events. Neither, however, must he be ungracious. Bringing his prayers to a decorous pause, he got slowly to his feet. His knees were like the rusted hinges of an old door. He assumed the villagers were delivering bread and water, and indeed, when he turned, he saw the silhouette of the boy, Jarwal, standing in the notch in the southern wall that must at one time have been a window. But Jarwal was reaching down and hoisting a second person up beside him.

Another ogler come to see the hermit? He had asked that such people be gently dissuaded wherever possible, but some were wealthy, the villagers were poor, and he relied upon their goodwill.

The second silhouette was that of a robed woman, and if she was an ogler then she was a very insistent one because Jarwal was helping her climb down the slope of tumbled stones to the floor of the courtyard. He raised his hand intending to shout, ‘Stop!’ but he had not talked, let alone cried out, for a very long time and no sound came from his mouth.

The woman was walking towards him carrying a basket. He did not want to be in the company of a woman. She was, thank God, not one of the phantoms who stepped naked from the shadows in the middle of the night. If the visitor were a man he might have been carrying news of sufficient weight to justify breaking the intrusion, but no one would entrust a woman with a task of such import.

She stopped a few paces in front of him and put the basket down. Ten loaves and three leather bottles of water. ‘I gather these are yours.’ The voice was so familiar it could have emanated from inside his own head. She pushed her hood back and looked around. ‘I had heard that it was austere but I did not expect quite this level of ostentatious self-flagellation.’

He felt giddy. His sister had become a woman. ‘You . . .’ He sounded like a raven. He coughed to clear his throat and tried again. ‘You should be in the convent.’

‘Don’t worry. I’ll be going back.’

‘As for ostentation . . .’ He coughed again.

‘I have no money of my own. You gifted the order the little wealth you did not give away. They are, in consequence, the only people who will look after me. Unless I can find myself a husband. Which is not easy from inside a convent.’

He was about to defend himself but she cut him off for a second time. ‘You sold me to nuns.’

‘I didn’t sell you to anyone.’ His sister seemed as unwilling to take instruction as she had been when she was a child, and the convent had not improved her. Arguing was pointless.

She sat down on a crumbled pediment, uncorked one of the goatskins, hoisted it to take a generous swig then tore the end from one of the loaves. It was hard to tell whether she was genuinely hungry or whether she was trying to goad him. ‘Father indulged you too much. You grew up thinking that constant praise was normal and that other people were unimportant.’

‘I care little for your opinions about me, but you should not speak ill of our father.’

‘The nuns are vile, by the way.’ She picked a tiny stone from the bread and flicked it away. ‘Unsurprisingly, the majority were deposited there by rich families who wanted them out of the way. It has made them very bitter.’

‘A life devoted to Christ . . .’

‘The ones with vocations are worse. Vinegary little witches. They need our money but they hate our company.’

He took a deep breath. ‘Did you come here with some serious purpose?’

‘Then Father died and there was no one to revere you. You couldn’t sing, you couldn’t paint, you couldn’t argue fluently. You had fallen off a horse so many times we lost count. You were neither intelligent enough to practise law nor diligent enough to handle other people’s money. But you had to be better than everyone else, didn’t you.’ She looked around scornfully. ‘So you picked a challenge too pointless for anyone else to better.’

She looked up at him and he saw that she was crying. ‘I could have been happy. I could have been a mother. You threw my life away in return for this.’ She hurled the remaining crust across the courtyard where it cartwheeled to a halt and lay in the little cloud of dry dust it had raised.

He was angry that she was so wilfully misinterpreting everything he had done. He was angry that she was dismissing his years of sacrifice as self-indulgence. He was angry most of all that she was able to stir up these violent emotions.

Then he was not angry. He was overwhelmed instead by a memory of standing in a sunlit courtyard. He was fifteen years old, his sister seven or eight. It was spring or autumn, the air neither too cool nor too hot. His mother was weaving on a small handloom, yarns of indigo, turmeric, kermes red. He could hear the splash and slap of the servant girls washing clothes in the trough in the adjacent courtyard. His father was elsewhere in a dark room, poring over diagrams and accounts. His sister sat cross-legged in front of his mother. She had arranged two clay people and a little clay horse on the stone in front of her and was making them act out some ridiculous drama. The sun falling through the quince tree littered the ground in the centre of the courtyard with tiny overlapping circles of brightness like fallen blossom.

Within three years it would be gone, his father left paralysed by a seizure then wasting away over the following months, barely able to eat or drink, his mother dying shortly after from the annual fever which swept through the city in the damp heat of summer.

His sister was right. He had been so consumed by his own grief that he had not considered hers. They had both lost their parents. He had been a young man, but she was still a child. How was it possible to be so blind for so long to such obvious facts?

An uprush of warmth towards his sister was overtaken by his shame at never having felt it before. He walked over and knelt in front her. ‘I am profoundly sorry. I treated you very badly indeed. I told myself that everything I did was done to serve the Lord. I should have remembered that serving the Lord means, first and foremost, looking after one’s own family.’ He felt better for having simply spoken the words out loud.

She stared blankly at him as if he had spoken in a language she did not understand. ‘I am forced to sleep on a straw mattress in a room with five other women. One of them has lost her mind and whines constantly like a sick child.’

‘You have every right to be angry with me and I am painfully aware of my having no means of recompense for the wrong I have done you.’

He paused. He couldn’t say, at first, what caught his attention. Some animal faculty was warning him of danger. He remained perfectly still for a few moments. He could hear his sister breathing, the soft hush of windborne sand moving across stones and, every few seconds, the clang of a goat bell.

Then he smelled it, the faintest trace, the stink he had not smelled since the day some months back when a hyrax died and burst and oozed and dried up in the courtyard, felled by a sickness so vile that even the birds of prey would not touch the corpse. He felt sick in both body and spirit.

‘Brother . . . ? Something is wrong.’

He forced himself to ignore the voice of doubt. He had to do this and he had to do it quickly. He stood up, lifted his arm and struck his sister hard across the face so that she was thrown on to the ground by the force of the blow. She lay there not moving for what felt like a very long time indeed, then lifted herself slowly back on to the pediment, the red print of his hand bright on her cheek. ‘And this is how the famous holy man behaves to his own sister.’

‘You are not my sister.’

He wondered briefly whether he had made the most terrible error, then she let out a long growl and her eyes turned black. Her skin smoked and crackled and split and peeled away like the skin of a rabbit being roasted over an open fire. The same stink but overpowering now. He stepped backwards. She had been transformed into a hairy, snarling ape, spittle flying from her mouth. She sprang on to his chest, knocked him to the ground and fastened her sinewy hands around his neck. ‘You doubted. For a few minutes you doubted everything. I came so close. Next time I will shatter you completely.’

There was a bang as loud as a house collapsing and the creature exploded, covering him in clumps of brown fur and gobbets of sticky fat bearing the same foul stink, which he had to peel away one by one before washing himself with a mixture of dust and precious water.

He felt wounded over the following weeks in a way that he had not felt wounded before, and it took longer for him to heal. He had been blindsided. He had won the battle but the margin by which he had done so was terrifyingly thin.