The ground was complex. The tractor’s lights showed how the ice was stained pink, as if by traces of blood, and there were streaks of darker material laid over the surface. But here and there the dirty water-ice rock was overlaid by splashes of white, brilliant in the lights; this was nitrogen snow, fresh-fallen.
The land became more uneven. The tractor climbed a shallow ridge, and Madeleine found herself tipped precariously back in her seat. From the summit of the ridge she caught a glimpse of a landscape pocked by huge craters, each some thirty kilometers wide or more. But they weren’t like impact craters; many of them were oval in shape.
The tractor plunged into the nearest crater. The ground broke up into pits and flows, like frozen mud, and the tractor bounced and floated in great leaps.
“This is the oldest surface on Triton,” Lena said. “It covers perhaps a third of the surface. From orbit, the land looks like the surface of a cantaloupe melon, and that gave it its name. But this is difficult and dangerous terrain.” Her accent was odd, shaped by time, sounding strangulated to Madeleine. “These ‘craters’ are actually collapsed bubbles in the ice. They formed when the world froze… You know that Triton was once liquid?”
“After its capture.”
“Yes.”
“Neptune raised great tides in Triton. There was an ocean hundreds of kilometers deep — crusted over by a thin ice layer at its contact with the vacuum — that stayed liquid and warm, for half a billion years, as the orbit became a circle.”
Madeleine eyed her suspiciously. “Life. That’s what you’re getting at. Native life, here in the tidal melt of Triton.” Just as Ben had hinted. She wasn’t surprised, or much interested. Life emerged wherever it could; everybody knew that. Life was a commonplace.
“You know,” Lena said, “when we first came here we spread out from Kasyapa, around this little world.”
“You sang Triton.”
“Yes.” Lena smiled. “We made our roads with orbiting lasers, and we named the cantaloupe hollows and the snow fields and the craters. We were exhilarated, on this empty world. We were the Ancestors! But we grew… discouraged. Nothing moves here, save bits of ice and snow and gas. Nothing lives, save us. There aren’t even bones in the ground. Soon we found we had to ration food, energy, air. We mapped from orbit, sent out robots.”
“Robots don’t sing.”
“No. But there is nothing to sing here…”
Madeleine, with a sudden impulse, covered Lena’s hand with her own. “Perhaps one day. And perhaps there was life in the deep past.”
“You don’t yet understand,” Lena said, frowning. She tapped a control pad and the motor gunned.
The tractor followed complex ridge pathways, heading steadily away from Kasyapa.
They talked desultorily, about planetary formation, Lena’s long life on Triton, Madeleine’s strange experiences among the stars. They were exploring each other, Madeleine thought; and perhaps that was the purpose of this jaunt.
Lena knew, of course, about Ben’s relationship with Madeleine. At length they talked about that, tentatively.
Lena had known about it long before Ben had left for the stars. She knew such things were inevitable, even necessary, in a separation that crossed generations. She herself had taken lovers, even an informal second husband with whom she’d raised children. The ties of galay and dhuwa were, she said, too strong to be broken by mere time and space.
Madeleine found she liked Lena. She still wasn’t sure if she envied Lena the ties she shared with Ben. To be bound by such powerful bonds, for a lifetime of indefinite duration, seemed claustrophobic to her. Perhaps I’ve been isolated too long, she thought.
After some hours they reached a polar cap. It turned out to be a region of cantaloupe terrain where every depression was filled with nitrogen snow. They camped here, near the pole, on the fringe of interstellar space. Overhead, Madeleine saw cirrus clouds of nitrogen ice crystals.
The pole was a dangerous place to walk. She saw evidence of geysers — huge pits blasted clean of snow — and dark streaks across the land, tens of kilometers long, like the remnants of gigantic roads. All of this under Neptune’s smoky light, and a rich dazzle of stars.
This was an enchanting world. Madeleine found herself, reluctantly, falling in love with Triton.
Reluctantly, because, she was coming to realize, she would have to destroy this place.
Lena brought her, on foot, to a small unmanned science station, painted bright yellow so it stood out from the pinkish snow.
“We are running a seismic survey,” she said. “There are stations like this all over Triton. Every time we shake the surface, by so much as a footstep, waves travel through this world’s frozen interior, and we can deduce what lies there.”
“And?”
“You understand that Triton is a ball of rock, overlaid by an ocean — a frozen ocean. But ice is not simple.” Lena picked up a loose fragment of ice and cupped it in her gloved hands. “This form is called ice one. It is the familiar form of ice, just as on Earth’s surface.” She squeezed tighter. “But if I were to crush it, eventually the crystal structure would collapse to an alternative, more closely packed, arrangement of molecules.”
“Ice two.”
“Yes. But that is not the end. There is a whole series of stable forms, reached with increasing pressure, the crystal structure more and more distorted from the pure tetrahedral form of ice one. And so, inside Triton, there are a series of layers: ice one at the surface, where we walk, all the way to a shell of ice eight, which overlays the rocky core…”
Madeleine nodded, not very interested.
The snows seemed to be layered. The deeper she dug with her booted toe, the richer the purple-brown colors of the sediment strata she uncovered. This hemisphere was entering its forty-year spring, and the polar cap was evaporating; thin winds of nitrogen would eventually carry all this cap material to the other pole, where it would snow out. And later, when it was autumn here, the flow was reversed. Triton’s atmosphere was not permanent: It was only the polar caps in transit, from one axis to another.
But Lena was still talking. “…large scale rebuilding of the planet is the same as—”
Madeleine held up her hands. “You left me behind. What are you telling me, Lena?”
“That there is evidence of tampering, planetary tampering, from the deepest past, here on Triton.”
Madeleine felt chilled. “Even here?”
“Just like Venus. Just like Earth. Nothing is primordial. Everything has been shaped.”
That inner layer of ice eight was no crude seam of compressed mush. It was very pure. And it seemed to have been sculpted.
When they got back to the tractor Lena showed Madeleine diagrams, seismic maps. The core had facets — triangles, hexagons — each kilometers wide. “It’s as if somebody encased the core in a huge jewel,” she said. “And it must have been done before the general freezing.”
“Somebody came here,” Madeleine said slowly, “and — somehow, manipulating temperature and pressure in that deep ocean — froze out this cage around the seabed.”
“Yes.”
“And the life-forms there—”
“Immediately destroyed, of course, their nutrient supply blocked, their very cells broken open by the freezing. We can see them, their relics, in the deep samples we have taken.”
Madeleine felt a deep, unreasoning anger well up in her. “Why would anybody do such a thing?”
Lena shrugged. “Perhaps it was not malice. They may have had a mission — insane, but a mission. Perhaps they thought they were helping these primitive Triton bugs. Perhaps they wished to spare the bugs the pain of growth, change, evolution, death. This great crystal structure encodes very little information. You need only a few bits to characterize its composition — pure ice eight — and its regular, repeating structure. It is static, perfect — even incorruptible. Life, on the other hand, requires a deep complexity. It is this complexity that gives us our potential, and our pain. Perhaps, you see, they felt pity…”