Above her, the Xeelee nightfighter folded its huge wings.
Titan, Saturn’s largest satellite, was a world in itself: around three thousand miles across, larger than Earth’s Moon. As she descended, the cloudscape took on the appearance of an infinitely flat, textured plane. Huge low pressure systems in the photochemical smog spiraled around the world, and small, high clouds scudded across the stratosphere.
The first thin tendrils of air curled around the walls of the pod. Overhead, the stars were already misting out.
Suddenly the pod dropped, precipitously. She was jarred down into her seat. Then the little craft was yanked sideways, rocking alarmingly.
“Lethe,” Louise said ruefully, rubbing her spine.
Louise had left Spinner in the lounge, to follow the pod’s progress on the data desk. “Are you all right?” Spinner asked now.
“I’ve been better… I’m not hurt, Spinner-of-Rope.”
“You knew you had to expect this kind of treatment. Titan’s atmosphere is a hundred miles thick: plenty of scope for generating a lot of weather. And there are high winds, up there at the top of the atmosphere.”
It was quite dark in the cabin now; the opaque atmosphere had enfolded the pod completely, leaving only the cabin lights to gleam from the transparent walls.
Spinner went on, “And did you know Titan has seasons? It’s spring; you’ve got to expect a lot of turbulence.”
As the pod dropped further it shuddered against a new onslaught; this time Louise thought she actually heard its structure creak.
“Spring,” murmured Louise. “’Where are the songs of Spring? Ay, where are they?’”
“Louise?”
“John Keats, Spinner-of-Rope. Never mind.”
Now the buffeting of the little ship seemed to lessen; she must have passed through the high-wind stratosphere. She pulled out a little slack in the restraints which bound her to the seat. Beyond the hull, the cabin lights illuminated flakes of ammonia ice, and fine swirls of murky gas shot up past the pod and out of sight.
“It’s bloody dark,” she muttered.
“Louise, you’re dropping into a mush of methane, ethane and argon. It’s a smog of photochemical compounds, produced by the action of the Sun’s magnetosphere on the air — I can see a lot of hydrogen cyanide, and — ”
“I know all that,” Louise growled, gripping her seat as the pod lurched again. “Don’t read out the whole damn data desk to me. Photochemical compounds aren’t what I came down here to find.”
“What, then?”
“…People, Spinner.”
Once, this had been the most populous world outside the orbit of Jupiter: Titan had cradled mankind’s most remote cities. Surely — Louise had thought — if anywhere had survived the devastation that had struck the inner worlds it would be here.
She needed to see what was going on. Louise punched at the control pad before her. The walls of the pod faded to pearly opacity. She called for a Virtual image, an amalgam constructed of radar and other data.
Below her, in the pod’s Virtual windows, the landscape of Titan assembled itself, as if from elements of a dream.
She banked the pod and took it skimming over the crude Virtual representation, fifty miles above the surface.
Titan had a core of rock at its heart, clad by a thick mantle of frozen water ice. Beneath the obscuring blanket of atmosphere, eighty percent of the solid ice surface was covered by oceans of liquid methane and ethane, richly polluted by hydrocarbons. The remaining fraction of “dry” ice-land was too sparse to form into sizeable continents; instead, ridges of water-ice, protruding above the methane, formed strings of islands and long peninsulas.
Well, the oceans were still here. Louise let the ancient, familiar names roll through her head: there was the Kuiper Sea, Galilei Archipelago, the Ocean of Huygens, James Maxwell Bay…
But, of the humans who had once named this topography, there was no sign. In fact, it was as if they had never been.
Once, huge factory ships had sailed across these complex oceans, trailing high, oily wakes; enough food had been manufactured in those giant ships to feed all of Titan, and most of the other colony-moons in the Saturn system as well. There were no ships here now. Maybe, if she looked hard enough, she would find traces of huge metal carcasses, entombed in the ice floors of the chemical seas.
…But now there seemed to be something approaching over the tight-curving horizon: a feature which didn’t chime with her memory. She leaned forward in her seat, trying to see ahead more clearly.
It was a ridge of ice, looming over the oceans, stretching from side to side of her field of view as it came over the edge of the world.
“Spinner — look.”
“I can’t quite make it out — it doesn’t seem to fit the maps…”
“Maps?” Louise muttered. “We may as well throw the damn things out.”
It was the rim of a crater — a crater so huge it sprawled like an immense scar around the curve of the planet. Within the mile-high walls of the crater, a new sea, deep and placid, lapped its huge low-gravity waves.
“Well, that wasn’t here before,” Spinner said. “It’s wiped out half the surface of the moon.”
Louise had Spinner download projections of the crater’s overall shape, the deep profile hidden from view by the circular methane ocean it embraced.
Beneath the ocean surface the crater was almost cylindrical, with sharp, vertical walls and a flat base.
“Volcanic, do you think?” Spinner asked.
“It doesn’t look like any volcano mouth I’ve ever seen,” Louise said slowly. “Anyway, Titan is inert.”
“Then what? Could it be an impact crater? Maybe when the moons got broken up — ”
“Look at it, Spinner,” Louise said impatiently. “The shape’s all wrong; this was no impact.”
“Then what?”
Louise sighed. “What do you think? We’ve come all this way to find another relic of war, Spinner-of-Rope. Now we know what happened to the people. When whatever caused that struck Titan, the whole surface of the moon must have convulsed. No wonder the cities were lost…”
She imagined the ice-ground cracking, becoming briefly liquid once more, swallowing communities whole; there must have been mile-high tidal waves in the low gravity methane seas, overwhelming the food ships in moments.
Spinner was silent for a while. Then, “You’re saying this was done deliberately?”
Louise smiled. Superet, reconstructing the future from the glimpses left by Michael Poole’s encounter with the Qax, had come across the concept of a starbreaker: a planet-smashing weapon wielded by the Xeelee — a weapon based on focused gravity waves. Superet had even had evidence that a starbreaker of limited power had been deployed inside the Solar System itself: by the Qax invaders from the future, during their failed onslaught on the craft of the Friends of Wigner.
She said to Spinner, “You ought to be getting used to this by now. We know the Xeelee had weaponry sufficient to destroy worlds. For some reason they spared Titan. Instead — they wiped it clean. Just as they did Callisto.”
Louise took the pod down to one of the largest individual islands, close to the rough rim of the Kuiper Sea. There was a soft crunch when she landed, as the pod crushed the friable-ice surface.
A small airlock blistered out of the side of the pod’s hull, and Louise climbed through it.
Instantly she was enclosed by a shell of darkness. In the murk of photochemical smog, her suit lights penetrated barely a few feet. Looking down she could only just make out the surface. Under a layer of thick frost, which creaked as it compressed under her boots, the ground was firm, flat. She lifted herself on her toes, trying her weight; she felt light, springy, under Titan’s thirteen percent gee. There was a soft wind which pushed at her chest.