Freya stopped to rake the dirt out of a furrow. It was stickier than usual, and darker—not quite like soil, but not as loose and powdery as the fine gray dust that blew across the plain.
The rake met an obstruction. Freya kneeled down and started scooping the dirt aside with her hands. She could smell a buried fragrance rising from the furrow—several odors, in fact, some sweet, some pungent.
As the dirt parted from the thing it had concealed, she saw it plainly: a fully formed root flower, with six cooling petals arrayed around the central stalk. Freya laughed with delight; a shallow burial in such porous material probably hadn’t been doing much to limit the flower’s outgassing, so this didn’t really count as a victory for the atmosphere, but it was still more than she’d expected to find. Why hadn’t this root given up while the whole plateau was still above it, when so many others had barely made it within sight of the surface, down on the plain?
She spent a while savoring the discovery, brushing off as much of the clinging, aromatic dirt from the flower as she could, as if she were cleaning an old agricultural implement she’d chanced upon buried in a field. Then reluctantly, she rose to her feet and continued.
A few furrows later, she found a second flower, similarly buried in the dirt. Then a third, and a fourth. She was beginning to wonder if anyone would believe her when she reported the finds, even if she declined to claim them for her tally.
When the string of successes petered out, Freya wasn’t surprised; the cluster must have come from rootlets branching off from a single, tenacious progenitor—one chance event out of sight to explain all four on the surface. Nonetheless, as she paced back and forth across the plateau three more times without another sighting, she found it harder to resign herself to the outcome than before, when she’d expected nothing.
And after one especially deep and dirt-filled furrow proved flowerless, her disappointment took hold of her. She swung her pick into the ice: six blows, a dozen, eighteen. She stopped, feeling foolish; she didn’t have the time or energy to waste on pointless acts of frustration. And she very nearly walked on without even clearing away the shattered ice, but then that seemed doubly wasteful, so she squatted down and started pulling the shards out of the pit she’d made.
There was a root. She’d damaged the top of it with the pick, and it was seeping sweet-smelling alkanes onto the ice, but if she exposed some more of it, more carefully, there was no reason why the unbroken part wouldn’t shed the injured section and flower.
When she was done, she went back to the previous barren furrow and attacked it. There was nothing to be found, at any depth she could reach. She went to the furrow before it, and tried again, stopping to remove the fragments of ice after each blow. There was a root not far below the surface—out of sight when she’d first looked, but the ice here could obscure anything.
By the time Freya had backtracked all the way to the fourth of the dirt-buried flowers, she’d exposed nine roots. She stopped to catch her breath, happy but bewildered. If the pattern continued, she’d have no hope of exposing every accessible root on the plateau before nightfall—which was glorious, but utterly perplexing. How could this much extra ice be anything but an obstacle? What was it that she didn’t understand?
“It’s not about how far the roots have grown,” Bridget argued. “It’s about how hot or cold they are. If you pile up a lot of extra ice above the plain, that’s going to trap the heat: if you dug down a couple of hand’s breadths from the top of your plateau, you’d find it was every bit as warm as if you did the same anywhere on the plain. So the root tip isn’t going to stop growing, just because it’s come a long way from the ocean. It will only stop when it’s cool enough.”
“That makes sense,” Freya conceded. “But it doesn’t explain everything. The top layer of ice on that plateau has more roots in it than anyone’s found on the plain. I can see why it might be the same, but… why more?” She looked around the table, trying to judge her friends’ moods; she didn’t want to annoy anyone by seeming to gloat about her find. But it was still too strange and wonderful to be treated as purely a matter of chance, requiring no further discussion.
Erna said, “You mentioned a lot of dirt in the furrows?”
“Yes.”
“That would trap the heat even more, wouldn’t it? And it would reflect less sunlight than bare ice.”
“Right.” Freya felt a little foolish now; everyone knew that dark objects grew warmer than lighter ones. “So maybe the real puzzle is why the furrows are so deep.” Given their shape, it wasn’t surprising that they filled up with dirt, but even if it would take eons for the whole plateau to be eroded away, it seemed odd that the wind hadn’t yet sandblasted the top of it flat.
“I wonder what happens when a root flower is buried in a little valley like that,” Gro mused. “I mean, it’s still giving off methane and water vapor, but how freely does it all escape?”
Hanna said, “The methane would pass right through the dirt, but I think most of the water vapor would freeze on the grains of sand.”
Freya looked at Gro, wondering if they were thinking the same thing. But if they were, Gro offered her the chance to speak first.
“The whole shape could be a kind of growth pattern,” Freya said. “The dirt in the furrows traps water vapor from the root flowers as it turns to ice. That ice piles up, the furrows grow into mounds, and all the dirt that blows in on the wind spills off them onto the old mounds—which are now valleys and furrows themselves. And so it all starts again.”
Hanna laughed. “So the roots keep re-burying themselves in ice made from the very water they’re trying to get rid of! Which means they’re raising the plateau higher and making their own job harder—but as long as there’s enough dirt around to keep them warmer than they want to be, they’ll keep trying to push their way up into the cold.”
Gro said, “If that’s really what’s happening, I don’t know if we should be surprised that it’s the first time we’ve seen anything like it—or surprised that the phenomenon isn’t so rare that no one’s ever witnessed it at all.”
Freya wasn’t sure that they’d solved the mystery, but she doubted they’d come up with a better explanation if they sat around talking all night. Every scrap of food had vanished from the table long ago, and they’d all have to rise at the usual time in the morning.
She said, “To be honest, I haven’t worked as hard as I did today since my first harvest. Whatever made the plateau the way it is, I’m going to need to get to sleep soon or I won’t be able to face it again tomorrow.”
Bridget said, “You do know that we’re all coming with you, to help?”
Freya glanced at the others, but they seemed to be in agreement. “What about your own patches?” she asked.
“We’ll return to them when the plateau’s done,” Hanna replied. “If that’s where the roots are, that’s where our time’s best spent. No one expects you to break your back trying to get through all the work up there, alone.”
As the five friends set off across the ice together, Freya wondered if her companions were sufficiently awake yet to hear the wild thoughts that had kept her from sleep. She wasn’t even sure that she was in any state herself to decide what was worth repeating. As she’d lain on the blankets with her limbs aching, picturing the roots that stretched down to the buried ocean beneath her, the ideas that flowed through her head had seemed urgent and compelling—for all the uncertainties, and all the questions they raised. By daylight, the case was not so clear.