Javeed said, ‘If you get scared, just give it the thumbs-down.’

‘Okay.’

One of the king’s advisers approached Shahin and spoke to him quietly.

Shahin passed the news on to his staff. ‘The king has called for my service, and I am to bring the two lightest of my apprentices.’ Javeed was a shoo-in, obviously, but Martin was preordained to be a passenger too, which might have explained why his three competitors were all tall and solidly built. He didn’t even need to point out that he’d lost ten kilos in real life since his icon was snapped.

Kavus seated himself on his royal throne and a flunky closed the tent flap so His Majesty wouldn’t have to watch the staff carrying on untidily around him. Martin and Javeed followed Shahin onto the pavilion, where they set about priming the aircraft’s engines: hooking pieces of rabbit meat onto spikes that protruded from the forty-eight rods, just out of reach of the tethered eagles. Javeed was too short to reach the spikes himself, so his job was to carry the pail of meat and hand chunks to the two adults. The birds, still blinded, did not react to the meat, but at the sound of approaching footsteps some of them chafed against their constraints, tugging on the ropes in random directions as if to signal their annoyance to their captors.

When the preparations were complete, Shahin spoke with the adviser, who approached the royal enclosure.

‘Lord of the World, Jewel of Persia, your good fortune brings justice and happiness to all your people.’

Kavus emerged from his tent and gazed up into the sky. ‘No human before me, however great their birth and station, has dared attempt this feat; none after will have the courage to repeat it.’ He looked down and stretched out his arms towards the gathered observers. ‘The glory of this day will be burnt into your memories, as the image of the sun sears your vision.’ They bowed their heads in agreement, then began retreating to a safe distance.

The adviser remained on the platform; now he signalled to Shahin to proceed. Shahin directed Martin and Javeed to two different starting points, separated by a third of the platform’s circumference, then took up a position himself equidistant from both of them.

Kavus thumped the shaft of his mace against the wicker floor and cried out, ‘Now I join the angels!’

They began unhooding the eagles.

The first bird whose sight Martin restored paced the floor irritably for a few seconds, then feinted towards his hand as if to bite it, but once it noticed the meat dangling above its head it flapped its wings and rose into the air as far as the harness would allow it.

When the ropes grew taut, though, it seemed to grasp the nature of its situation perfectly, because it gave up struggling and returned to the floor. It knew it couldn’t reach the meat; there was nothing to be done but wait for the humans’ next bizarre, capricious action.

Alarmed, Martin looked to Shahin. His bird was on the floor too, but he was encouraging it with a series of nods and grunts; perhaps these were signals used in hunting. After a few seconds, Shahin’s bird heeded the cues and flew up towards the lure.

Martin turned to see what Javeed was doing; he was already mimicking Shahin. Martin felt weirdly self-conscious; the noises were embarrassing enough coming from Shahin, and his own attempts would surely sound sillier: all this, in the presence of royalty. But the Lord of the World would be even less pleased if his precious sky-pavilion toppled over on the grass, unbalanced by one tardy peasant.

Martin faced the eagle again and tipped his head skyward, grunting and snorting. The eagle blinked at him bemusedly. What was it waiting for – should he mime taking flight himself? If it had been a seagull he might have flailed at it with his hands to drive it off the ground, but his instincts warned against trying that on a raptor. He looked back at Javeed, whose bird was airborne now; it was straining against the harness as if the hunk of rabbit flesh just beyond its reach were a pigeon fleeing across the skies. Now there was an idea for Kavus’s next version: harness some actual living prey, and maybe take-off would proceed more smoothly.

Javeed made a guttural noise. ‘Like that, Baba!’

Martin imitated him. Nothing. He tried again, deeper in the throat, while flicking his head up encouragingly; finally, his eagle took flight, and when it reached the end of its tether it remained aloft. Maybe you had to be a native Farsi speaker for the right sound to come easily.

The three of them moved around the pavilion, unhooding the eagles and encouraging them to persist in their futile attempts to reach the lures. Martin still had the most trouble persuading his birds that they should mush like sled dogs, but Shahin and Javeed waited for him; if they’d raced ahead at their own pace that would have risked unbalancing the whole structure.

When Martin set his tenth bird in motion, the pavilion lurched and began to weave across the grass like a hovercraft with broken steering. Apparently the combined effort of thirty golden eagles – according to the game’s fanciful notion of their power – was enough to overcome the weight of the craft and its passengers; with friction all but banished, the imperfect cancellation between the horizontal thrust from the variously inclined tug-ropes was enough to send the pavilion skittering in all directions. The field was wide and there were no obstacles nearby, but the earthbound observers wisely mounted their horses and retreated further from the action.

Javeed was beaming with delight. ‘Hold on to the rods!’ Martin warned him; Javeed nodded and took hold. Martin wasn’t sure if it was entirely logical – nothing Javeed did could actually support him in his ghal’e; holding thin air wouldn’t help him stay upright when the real floor beneath his feet tilted – but it was a good habit to cultivate regardless, and it could certainly affect what the game did to his icon. Martin was feeling slightly queasy from the visual cues alone; if anything, the fact that he could feel himself lying flat on his back, motionless in the scanner, exacerbated his discomfort as his eyes told him he was zigzagging across the grass. But it was worth it just to see Javeed so happy. If the worst happened, Martin decided, Bernard would probably manage to stop him choking on his own vomit.

Kavus was standing in front of his tent, trying to appear regally composed even as he swayed like a sailor on a storm-tossed deck. His adviser, who’d wisely gripped the side of the tent, looked as sickly as Martin felt.

Shahin called out, ‘Come on, get to work! The next three together!’

Martin unhooded his eleventh eagle; it regarded the mad, sliding world around it with a look of doleful avian stoicism. ‘On the count of three,’ Shahin shouted. ‘One. Two. Three!’

Martin grunted at the bird and flicked his head. It rose from the platform, and when its tether snapped tight the pavilion’s motion suddenly became smoother. Martin peered over the edge. Before, they’d been scraping the grass, brushing against every second tussock; now they were clear of the vegetation, half a metre or so above the ground and still rising.

‘Again!’ Shahin urged them. Martin hurried to unhood the next bird. ‘One. Two. Three!’

They quickly brought the last of the eagles into play. By the time Martin had a chance to look around again they were higher than the treetops – which was lucky, because they were drifting straight towards the cypress grove.

‘The Lord of the Earth becomes Lord of the Sky!’ Kavus proclaimed modestly. ‘Ten thousand generations will not see the equal of this feat!’

‘Lord of the Earth… Lord of the Sky,’ his adviser mumbled. The poor man did not look well.

The pavilion passed over the grove, safely clear of the highest branches. Martin took a step towards Javeed, then he felt the platform tilting and retreated. Though Javeed was lighter than his two fellow bird-wranglers, Kavus and his adviser must have been far enough from the centre to help maintain the balance. But the luck – or contrivance – that had granted them a level ascent meant that any change now was risky. If they moved at all, it would have to be coordinated very carefully.