‘Are they artificial?’

‘Oh, no. Well . . . not exactly. They were terrestrial animals that died out during Earth’s last ice age; then the Genome Structure Foundation sequenced their DNA from mummified remnants dug out of the Siberian permafrost. Controversial at the time, especially given what that particular foundation morphed into, but we wound up taking them to half the planets we settled, them and the crudding dodo – though what the point in recreating that was I’ll never know. Dumbest creature ever, and as ugly as sin too. Plus, it tastes exactly like chicken, so that wasn’t a valid reason, either.’

‘It sounds very worthy, bringing the species back from the dead. I know Earth was in big ecological trouble at one time; that was in my general history memory.’

‘Yeah. We had a bit of a guilt overreaction to that. It’s called Sanctuary: the only world we ever terraformed from scratch. Two hundred years dumping billions of tonnes of microbes and biogunk onto it to prepare its atmosphere and sand for terrestrial plants. Another century bombing it with seeds and insects before we went all Noah on its ass and released our animals two by two. Every species but humans – oh and wasps, I think. It’s the only true pure copy of Earth’s biosphere in the galaxy, and we’re the one lifeform that’s banned from it. Brilliant! But hey, there are lots of whales in Sanctuary’s oceans. Always whales. We have such an ingrained collective culpability trip over them. So that’s okay.’

‘You sound so cynical.’

‘That’s self-deprecation,’ Fergus said. ‘He’s not sorry about Sanctuary at all. Who do you think paid for it?’

‘That was necessary,’ Nigel said. ‘An experiment.’

‘Experiment?’

‘Yeah. See, there’s a lot of H-congruous worlds in this galaxy; the biochemistry is different, but not lethally so.’ He gestured round. ‘Like here, we co-exist happily; there’s even some native plants we can eat. But if our colony fleets got to another galaxy and the majority biochemistry was incompatible, we’d have to know how to terraform, and get it right. Best we find out how before we go.’

‘Another galaxy?’ Kysandra pressed her hands to her temples. ‘Is there really no way I can get out of the Void? I want to live out there. I want to be free.’

Nigel gave her a sorrowful look. ‘Sorry – me and my mouth. I’ve got to learn when to shut the crud up.’

‘No,’ she said. ‘Don’t do that. Not ever.’

*

In the morning they dressed in their desert robes – a silverwhite cloth that had the same thermal properties as the tent fabric. It was also used in the wide floppy hats they made the horses wear to protect their heads from the direct power of the sun.

Kysandra carefully wrapped the turban round her head, making sure she tucked all her hair away from her face. With the cloth wound tight, it was difficult to make sure her darkened goggles fitted properly.

‘I can hardly move my jaw,’ she complained.

‘I’ll refrain from the obvious comment,’ Nigel said, and stood in front of her, adjusting the strips of turban she’d wrapped below her chin. ‘How’s that?’

‘Good, I guess.’

‘You ready?’

‘Uracus, yeah.’

They rode their horses out past the foothills, where the last tufts of vegetation clung to the floor of shallow gullies, and moved out into the dunes of the desert itself. Nigel and Fergus checked how the tyres were dealing with the hot grey sand, but they appeared to be coping okay. Certainly the bladder carts rolled along smoothly enough.

An hour after they started, Kysandra was glad of the desert robes. She’d felt as if she was swaddling herself when she put them on, they seemed so restrictive. But, sitting in the saddle as her horse plodded along, she didn’t have to exert herself. The cloth’s shiny surface reflected the sun’s heat away, while the thermal shielding prevented the hot air from scorching her skin. Except for breathing. The air was hot in her mouth, almost painfully so, quickly drying her throat out. She sipped constantly from the tube that snaked up from the flask strapped to her stomach under the robes. As the morning progressed, the desert’s eternal heat was something she was highly aware of, enveloping her completely, yet never managing to break through her protection. It felt exciting, defying such a hostile environment. She began to wonder if those audacious early explorers had actually found anything. Surely no one would be mad enough to trek to the middle of the desert as they were doing. Are the legends of bones just heat fever dreams?

The dunes began to grow larger, the sand looser. The course Nigel set, taking them to the heart of the desert, was always on a slope, going up, then down. Never following a flat gradient. Soon the foothills vanished from sight; only the Bouge mountains remained, implausible pinnacles of snow glinting above the desert.

The fiery air was saturated with minute particles, stirred by the mild but constant breeze. Despite the robes, they began to creep in through the folds to scratch her skin. She was blinking a lot now, small tears flushing her eyes clean. Her horse shook its head constantly at the irritation, whinnying protests at the awful heat. She had to send constant ’path orders, keeping it on track, soothing its mounting agitation at the harsh white-glare landscape. Only the mod-horses plodded on, unperturbed by their ordeal.

After four hours, Nigel called a halt in the lee of a tall dune. ‘I miscalculated,’ he announced. ‘This temperature is getting dangerous to the animals. It’s crazy to travel in the day, especially midday. We’ll make camp here until evening, and travel at night.’

Kysandra didn’t complain. She wanted to get on and reach the centre of the desert to solve its mystery. But her horse was becoming increasingly skittish, and she was picking up its genuinely distressed thoughts. As she climbed down she was startled by the sudden outbreak of noise from the poor animal. The desert had been devoid of any sound since they entered it. When she pushed up her goggles to wipe her eyes, the brightness was shocking.

They rigged up a big awning, and tethered the animals – not that they would have run off anywhere. Then she helped Madeline and Russell pitch the tents while Nigel and Fergus inspected the axles on the bladder carts, injecting fresh oil into the bearings to compensate for the sand that had got in.

Kysandra was impatient to get the tents up. The bizarrely contradictory feeling of claustrophobia the robes produced as she walked around slotting poles together and screwing pegs into the sand was making her edgy. As soon as she had watered and fed her horse, she hurried inside and stripped down to her underwear. The air within the tent was hot, verging on unpleasant, but she didn’t mind that; the absence of the robe was liberating. She took a long drink from the chillflask, gasping at how cold it was – only just above freezing.

‘Coming in,’ Nigel ’pathed.

Kysandra pulled a shirt out of her duffel bag and slipped into it.

‘How are you doing?’ he asked as he started to take his robes off.

‘I’m going to need more ointment,’ she admitted. The backs of her legs were still red and sore despite the salves she’d used every morning and night.

‘Me, too.’

‘Do you think the horses will be all right?’

‘The temperature is a lot lower under the awning. They’ll cope. And it should get cooler in here too, as long as we don’t keep opening the flap. Give it an hour.’ He dropped his robe on the floor.

‘Good.’ She unrolled her bedding and waited for the self-inflating mattress to plump up. ‘And you were worried about us freezing at night.’

‘Even I can be wrong. Who knew?’

She lay back on the mattress, telling herself she was slightly cooler. ‘So we’re just going to stay in here together for the next seven hours?’ Even now she couldn’t bring herself to share a tent with Madeline, or Russell. And Fergus was outside under the awning with the horses, keeping watch, as always.