Hex was distracted by a shadow crossing the cave mouth.
Hella was growing excited. ‘Pilot, I think I’ve figured it out—’
‘Shut up,’ Hex hissed. The shadow crossed again. Now she was sure: it was a palette-ship, and four, five, six Ghosts, angular rhomboids, rode it menacingly. Hastily she shut down their packs, and made her crew lie flat. Even Swimmer lay still in his puddle of slime.
The palette paused briefly at the cave mouth, but anything within was hidden by the fire. With a careless burst of an energy weapon the Ghosts smashed Swimmer’s hearth, scattering its fuel. Then the palette moved on.
The crew stood up cautiously.
Borno said, ‘So they’re looking for us. We have to get out of here.’
Hella grabbed his arm. ‘Not before you listen to me. I’ve worked it out. This world is—’
‘The home world of the Ghosts,’ Borno said, dismissively. ‘And this is their origin, from a million years back or so, somehow brought forward in time. Isn’t that obvious?’
Not to Hex. Her jaw dropped; she deliberately closed it.
Jul was figuring it out too. ‘Yes, yes. Swimmer speaks a variant of one of their languages. Ghosts are cooperative organisms, just like Swimmer. Even their hides were once independent creatures—’
‘Every Ghost is a whole ecology in a sack,’ Borno murmured, repeating training-ground lore.
Hella said, still excited, ‘We even found a copy of this system thirty light years away! That must be the present-day copy – this one is dredged up from the past…’
Jul said, ‘The “primitive” Ghosts must come from this world. The Black Ghost recruited them here.’
‘Maybe that’s why this was done,’ Borno said darkly. ‘The Black Ghost has tapped its own deep past for raw material for the war with humans. When Ghosts told us about their origin they never mentioned this devastating civil war, did they? Funny, that.’
Hella turned to Hex. ‘Pilot? You’ve been very quiet. What are you thinking?’
Hex looked at her, abstracted. ‘About time travel.’ Humans had achieved time travel, of course. Every faster-than-light ship was a time machine, and it was said that in the old days the legendary hero Michael Poole once travelled through time in a wormhole. ‘We’ve sent a few people, a ship or two, through a few centuries. But the Ghosts have brought a star system, a whole system, up through a million years.’
That sobered them.
Jul said, ‘The Integumentary did say that their new extra-dimension technology was opening up vast energy sources for them.’
‘Yes. But I never dreamed it would be capable of something like this.’
‘And,’ Borno said coldly, ‘it’s in the hands of the Black Ghost.’
‘So we have to stop it,’ Hex said. The others nodded, determined.
‘All right,’ Hella said. ‘But how? We’re still stuck in this cave.’
‘We have to get off the planet,’ Hex said. ‘And as far as I know the only launch capabilities are the nightsiders’.’ She considered Swimmer. She wondered if he knew he had been projected into the farthest future of his own kind. ‘Hella, do you think your new friend could help us get across the terminator?’
V
Under the guidance of Swimmer-with-Somethings, they journeyed north. They would cross into night somewhere near the planet’s spin pole.
The journey took them days – Earth days. They travelled out of sight of the ur-Ghosts, as they took to calling them, these cousins of Swimmer hardened for space but not yet of the optimal spherical form they would reach later. They clambered through tunnels, along the shadowed floors of deep ravines, and swam under the sea, their suits’ inertial control packs labouring to keep up with Swimmer’s economical motions. When they stopped, while the humans tended their blisters, Swimmer huddled in a gelatinous mass in any sunlight he could find, or, if they were in the ocean, he discorporated with exuberant relief. It was a mystery to Hex how the little shrimps and algae and amphibians that made up his body knew when to come back, and how to reintegrate.
As they forged steadily north the sun slid down the sky, and the shadows stretched long and deep. In the dimming sky Hex glimpsed stars, and the single bright pinpoint, steadily tracking, that was the Black Ghost’s habitat.
At last they came to a place where the sun sat on the horizon, glowing like hot coal. It looked as if it was about to set, but of course it never would. Life was sparse at this high latitude. An analogue of grass spread across the ground, though its native photosynthetic chemicals made it black, not green. But nothing grew in the long shadows, on this world where every shade was permanent.
Swimmer left them here. Unable to tolerate freezing temperatures, he could go no further. ‘Fight well for me,’ he said to them through Hella’s translator box. Then he squirmed away, like rainwater disappearing down a drain.
Hex looked north into the darkness. She saw motion: palette-ships, patrolling this boundary between day and night.
Borno pointed. ‘There are structures over that way.’
‘Let’s get on with it,’ Hella said tautly.
Following Borno’s lead, they walked into the night. Hex could sense Jul’s fear, Hella’s tension, and Borno’s grim, bloody determination.
The sun disappeared altogether. They passed a few last trees, so tall that their leaves blazed in sunlight while frost gathered on their roots. ‘Interesting bit of biomechanics,’ Jul said nervously. ‘They must have evolved to exploit the temperature differences between their crowns and their roots. And I guess these last trees must be as tall as this stock can grow, otherwise—’
‘Shut up,’ Borno hissed.
They came to a wall. It was just a heap of what looked like sandbags, glowing silvery in the dim light. They crouched behind this and cautiously peered at the structures that lay beyond.
Hex saw a kind of city, spun out of silver and ice, resting on a black velvet landscape. Necklaces swooped between cool globes, frosted, icicles dangling. Sparks of light drifted between silvered domes: Ghosts, or ur-Ghosts. The place had an organic look, as if it had been grown here rather than planned. But there was nothing of Swimmer’s vibrant, swarming physicality to be seen in this chill place.
This was a typical Ghost colony. Ghosts stayed away from the heat of stars, but they had remained planet-dwellers; they tapped a world’s geothermal heat for their energy, just as they evidently had on this, their own freezing world. And their colonies always had this tangled, unplanned look.
There were anomalies, though. On a slim spire that towered over the reef-city, a light pulsed steadily, brilliant electric blue. And at the very centre of the township a squat cylinder brooded. Hex’s suit sensors told her this was merely the upper level of a complex dug deep into the ground, where thousands of Ghosts swarmed. This fortress, very unlike Ghost architecture, was the work of the Black Ghost, obvious even here, just inside the boundary of night.
Borno tapped Hex on the shoulder and pointed.
A handful of ur-Ghosts swarmed around a palette-ship on the ground. The Ghosts’ forms were variants of parallelepipeds, like slanted boxes. They were really quite beautiful, Hex thought, their facets flashing like mirrors in the starlight as they worked.
Borno whispered, ‘Four of them, four of us. We can take them out. And then we can grab that palette-ship and get to orbit.’
Jul hissed, ‘We only just crossed the terminator. Maybe we should go further before—’
‘What’s the point? We came here to find a way off the planet. There’s our opportunity.’ He raised his hand, holding a knife.