‘We have other words for it,’ said Benzamir, ‘but I understand now. This book that the emperor is so desperate to get – had you ever seen anything like it before?’

‘No,’ said Alessandra, ‘never. I brokered one of the deals, but it couldn’t be over fast enough for me. User machines are just things, but this was alive in a way that scared me. It was sold, I took my fee, and the buyer sold it on the next day for a fat profit. That was the last I saw of it, though I heard of it moving through the diggers and booksellers, back and forth, selling each time for ever-increasing amounts of money. A king’s ransom by the end. Then it went quiet.’ She turned slightly and took another look at Benzamir. ‘Are you really a magician?’

‘Really? No. Does anyone believe me when I deny it? No. It’s easier to answer yes.’ He looked at Wahir’s expectant face, then took off the metal skullcap, which was becoming uncomfortably warm. He rolled it around in his hands and continued almost at a whisper. ‘If I wanted to, I could destroy the emperor, reduce his palace to dust and scatter his armies to the four winds. But it’s always been easier to destroy than to build.’

‘You could do all that?’ asked Wahir.

‘Yes.’ Benzamir got up and walked away, and stared out into the eastern desert, towards the invisible mountains he might have called home.

Hesitantly Alessandra joined him. ‘You don’t look like that kind of man.’

‘Thank you.’

‘Are you boasting?’

‘No,’ said Benzamir. ‘We need to find some shade, or we’re all going to fry to a crisp, godlike powers or not. We need to clean your head up too. Come on, let’s get back to the carpet.’

As he stalked away back to where Wahir was waiting, Alessandra called after him. ‘I’ve made you angry. I’m sorry.’

‘No,’ he said without turning, ‘not angry. Sad. Every time someone finds out who I am and what I can do, they stop being my friend and start being my follower. I just didn’t expect that.’

They found shade in the shadow of a cliff wall after a short flight over the desert, past the point where the surface was merely stony and into the endless sand sea. There was a spring that trickled water down the rock and collected in a cool, dark chasm before it vanished in the blinding heat of the day.

Benzamir summoned another bright cylinder, but this time he pointed up into the sky to show where it came from. They followed where his finger led, and high up in the deep blue zenith a line of light was being drawn. Where the light faded, a tail of smoke appeared before being blown ragged by the wind. Then even the light went out.

The object plummeted to the ground a decent distance away, smacking into the ground in a high-thrown shower of sand. Benzamir went out to collect its contents.

After he’d brought back a single slim case, he said to Alessandra: ‘You’ll need to come out into the light where I can see what I’m doing.’

‘What are you going to do to me?’ she asked.

‘Stop you from dying. For today at least.’

She sat on a ledge of sandstone and looked fearfully at the case Benzamir opened. ‘What is that symbol? The red diamond?’

‘Traditional to my people. It means medicine.’ He was building a machine out of separate parts, twisting and pushing them until they clicked. ‘Tilt your head over away from me.’

She complied, trembling. He pressed the machine to her neck and she felt a sharp scratch.

Firstly, ‘Ah! What was that?’ Then, ‘I feel strange.’ Finally, ‘I . . . Benzamir?’

Alessandra leaned back, and her eyelids fluttered closed.

Benzamir put the gas gun back on the lid of the case, picked up a pair of long-handled scissors and started cutting the hair away from her wound. He worked quickly, cleaning the blood off in thin red rivers that stained the surrounding stone and applying a thin square of wet material straight from a sealed can. Then he reloaded the gas gun and shot her again in the neck. He moved her back into the shade and left her to sleep off the anaesthetic.

‘Master?’ asked Said. ‘What are you going to do with her now?’

‘I don’t know. What did you have in mind?’ Benzamir filled his water skin from the spring and upturned it over his head.

‘She knows of your powers. What’s to stop her from talking?’

‘Nothing, I suppose. Gratitude?’

‘Everyone has their price, master,’ said Said. ‘She used to be a slave. She knows that money will keep her free.’

Benzamir was silent in thought. When he looked up again, he asked, ‘Where’s Wahir?’

‘Exploring. The king who sent you wants you to find your enemies. Already some of the Ethiopian soldiers have seen your flying carpet, and your – you know . . .’ He pointed his finger, except that when Said did it, nothing blew up. ‘There have been two of your wondrous deliveries from the Heavens. Now you’ve healed this Ewer woman with your magic, and master, it’s dangerous.’

Benzamir put his hands to his face and slid them slowly down to his chin. ‘I know. It’s all very different to what I imagined. I thought I’d wander around, pick up clues, find the traitors and take them back. It’s a lot more complicated than that, Said.’

‘It’s like ripples, master.’

‘Ripples?’

‘Yes, a stone in a pool. The movement spreads outwards until all the surface is disturbed.’

After a while Benzamir said: ‘You know, you can be quite wise at times.’

‘Thank you, master. You have two choices. Stop making waves, or—’

‘Go faster, so that the waves will always be behind me.’

‘Yes.’

‘We need to find Wahir before he breaks his neck. I’ll take the carpet and have a look. Will you stay here with Alessandra?’

‘I’d rather not, master.’ Said looked away.

‘She’s unconscious. She can’t try and seduce you.’ Benzamir punched him on the arm. ‘It’s all right to like her. She is very pretty.’

Said folded his arms and narrowed his eyes. ‘She’s an infidel woman.’

‘And plenty of those never found their way into a harem, did they?’ Benzamir started for the carpet, still basking in the sun.

‘She could still ruin everything for you.’

‘Not if we run fast enough.’ Benzamir dug out the skullcap and slipped it on. The carpet rose into the air, turned lazily and met him halfway. He stepped on and sat cross-legged, just like he’d seen in the picture books. He ought to have a turban; instead, he wound his headscarf around his face until only a slit remained for his eyes.

The front of the carpet dipped as if bowing, then steadily accelerated until Benzamir’s kaftan was snapping and cracking behind him. Loose sand billowed up in his wake, two perfect spirals that arced upwards and fell back with balletic grace.

He turned, hard and tight. To his left, the desert. To his right, the sky. Straight ahead, the horizon running in a line up to down. Then he came back, gaining height, rising up the rocks like an eagle in an updraught.

Wahir was on top of the plateau, poking around inside a ruin, a black arched back with ribbing extending down into the dust.

‘Master, what is this? It looks like some great beast.’

‘It’s difficult to tell.’ Benzamir uncrossed his legs and found the ground. He patted one of the ribs, still upright but carved and worn by sand and time. He walked underneath it, and along the spine, picking his way over the half-buried debris until he was outside again. Diggers had been here before them. Only the ribs remained. ‘It’s an aeroplane,’ he said.

‘A what?’

‘A flying machine. These struts are some sort of composite, carbon tubes and resin. It used to have a skin, and wings, though they seem to have fallen off. There were seats, rows of them, all the way down. People travelled from city to city in them.’

‘Is it a User machine?’ Wahir got down on his hands and knees and scraped away some dirt near Benzamir’s feet. ‘Will there be anything working still?’