CHAPTER 30.
Helen wasn’t ashamed of having screamed as Zarathustra took a final sinking dive into the depths. If any occasion called for a scream, finding that you were about to plunge into a lightless, freezing ocean a hundred kilometers deep, drifting ever deeper until the rover you were in collapsed like an empty beer can in a sailor’s fist was exactly that occasion.
But she suddenly realized that they were slowing, coming to a halt. But there’s nothing under us! she thought. The lights were still working, and the water was empty below them.
Joe chuckled, then broke out laughing. “I thought I saw someone go past as we went down. Maddie, you genius!”
“What did she do?”
In answer, Joe climbed up the seats in the now nearly vertical Zarathustra—in fact, angled slightly more than vertical, tipping backwards a few degrees—and pointed up, to a point just below the front window.
Helen had to move upwards herself to get a look, but finally she spotted it: a sharp V shape, two white lines pointing directly at Zarathustra and then vanishing up into the bright ice above. “She got a line on us in that?” she said incredulously. “Maybe she is Supergirl.”
“If she was, she’d have lifted us out of the ice rather than leave us hanging,” said Joe, sounding his usual cheerful self. The tone lifted Helen’s spirits just by its comforting familiarity, even as she winced at the inevitable pun. “Still, I can’t complain, since we’re still alive.”
Helen noticed that her face was feeling chilly. “Oh-oh. Joe, I remember we had a discussion a while back about how vacuum wasn’t cold, so keeping warm wasn’t a problem. But—”
“But this isn’t vacuum, yeah. This could be a problem.” Joe was instantly serious, and lowered himself down to sit on the now-upright back of the driver’s seat, examining the controls. “Water, just about the worst-case, except maybe liquid helium or something. Still, I seem to remember…”
He fiddled with a few more controls. “Ah-HA! That’s it, the environmental offsets. Lessee…Well, they don’t go up quite that high, but she was meant to operate in places with atmosphere as well as vacuum, so I can crank our heat up some.” After a moment, “There, that’s got it. I think she’ll stabilize somewhere around ten degrees C—that’s around 50 Fahrenheit.”
“Is that all?” Helen felt a bit relieved. “We’ve camped in much worse, and these suits can handle the rest easily.”
There was a faint creaking noise as an unseen, lazy current swung Zarathustra around. The two froze, staring out in silence. “Can Zarathustra handle this, though?”
Joe shrugged. “I’m sure she wasn’t designed for an underwater plunge, unlike the probe capsule on Athena. But the fact I’m not seeing water down there at the bottom is a good sign. She’s holding the pressure—and it’s a fair amount of pressure. If we live through this, I’ll want to give her designers a big ol’ hug.She could spring a leak any minute, but we just have to hope that doesn’t happen.”
The elimination of immediate panic gave her a moment to realize something else was wrong. “Maddie? Larry? Anyone? Are you there?”
“Don’t bother,” Joe said. “Radio waves won’t penetrate water, at least not at the high frequencies we usually use.”
“Can we change the frequency?”
Joe thought a moment. “You know, we probably can. Most radios these days are actually just given a factory setting that locks the wavelength. They’re not like the radios from forty years ago that were built to handle only a very narrow band. And I’ll bet somewhere in the settings of these things there’s some flexibility. Maybe not enough, though. Getting through…” he glanced again at the rope, measuring, “…um, two, three meters of water and another half to one meter of ice with stuff dissolved in it, that’s going to be a challenge. In theory the software-defined radios are capable of almost any frequency, but in practice I dunno if I can get us down from the gigahertz range we generally play in—higher for some applications—and into the low megahertz I’ll need to penetrate the water.”
“Worth trying. We need to get some kind of contact going.” She glanced up again. So close. “Will they even be able to receive a signal like that, though?”
“If I don’t miss my guess, A.J. will be scanning every wavelength known to man until he gets you back. Don’t worry, if I start transmitting and it gets through, he’ll hear us.”
She sat on the back of one of the other chairs for a few moments, thinking. “What happened up there? I mean, I understand we had a quake, but I thought the water would keep on going up.”
“So’d I. I’m not sure, but I’d guess the cavern got sealed off, the evaporating water filled it with gas, and the floor was rising in the quake, squeezing the pressure higher.” He shrugged. “The fact is we’ve done a lot of lab playing with these things, but as anyone who’s worked with models can tell you, sometimes you get very strange shifts in behavior when you get enough bigger or smaller. We’ve never actually spent time on a planet at cryogenic temperatures and played around with massive amounts of water and supercooled ice. The physics doesn’t change, but the interactions of all the elements can surprise you sometimes. Probably some factor, or factors, that we just don’t know right now.”
He looked up from the panels he had been checking. “Well, it doesn’t matter what happened, it happened, and we didn’t get crushed, or worse caught in a short-lived tidal bore that froze us inside it. And we’re not going to freeze to death; temperature’s levelled out at 12 degrees C—almost 54 Fahrenheit.”
After a pause, she glanced down. “You know, the water’s actually not all that clear. I mean, it’s clear, so to speak, probably clearer than any water I’ve seen in an ocean back home…but there’s stuff drifting in it.” She let herself drop slowly to the rover’s rear window, stopping herself just short. “I can stand on this, can’t I?”
“Probably, but it’s taking a lot of pressure from the outside. Be on the safe side and don’t.”
She got her face closer to the curved reinforced diamond laminate window. “Definitely little particles. And the way the light shades—you can see that the water has very slow currents in it with different distributions of dissolved material, probably why you get that wavy striping in the ice.”
“So it’s circulating? Interesting. Why would that be happening? There’s no open ocean, no winds, no interaction with an atmosphere.”
“Well, you’ve got the squishing motion of Jupiter, first of all. If it’s dissipating enough energy to keep a hundred kilometers of ocean liquid, it’s moving it quite a bit.” She found the view somewhat vertiginous; there were no steady reference points, and as they were in fact over an effectively infinite abyss…“Larry and Anthony were torn over whether there’d be enough energy to give Europa an active rocky center, but if it is, then you’d have rock movement affecting things too. And—”
She froze for a moment, long enough for Joe to turn and say, “And?”
“Joe,” she said, very carefully, moving nothing but her lips, “get me camera three, the one we left in here. Make sure it’s set for minimum distance.”
“What’s up?” Joe asked.
She stared at the window, or rather, at what lay just a few inches beyond it.
Something almost transparent, a shimmer like a tiny sliver of ice.
But ice did not move against the drifting current with the blurred beating of tiny legs.
Joe arrived with the camera, followed her gaze, and stared. “No way.”
“It’s alive, Joe. Moving, eating, breathing extraterrestrial life!”
She started the camera running, glanced up at Joe, whose grin was slowly widening to match her own. She turned back, making sure the camera followed the little creature precisely. She couldn’t make out exactly what it looked like, but enhancement of the imagery would help there. The important thing was just to make sure this moment was recorded. Even if we don’t live to be rescued, someone may recover Zarathustra eventually. And this will be there, waiting. “Joe, since we are in this ocean, can you give me a reading on the oxygen concentration?”
“Do I look like A.J.?” Joe said, but without rancor. He clambered back up. “The external sensing suite wasn’t made with this in mind, but lemme try.”
A second creature joined the first, and the two moved around each other in a slow spiralling dance that she captured in the memory of the camera.
“Quite a bit,” Joe reported. “I can’t be sure, but I think it’s about ten to fifteen milligrams per liter. There’s a bunch of other stuff dissolved in it too.”
“My god. That’s…that’s more than enough to support just about anything from Earth. Anything water-breathing, anyway. And the temperature’s not much below normal freezing.” She shook her head, amazed. “And that colored stuff…has to be nutrients. Don’t know the source, but there’s an ecosystem here, Joe!”
The smile suddenly faded from his face.
“What’s wrong, Joe?”
“I just realized, we were looking at the whole situation wrong.”
Helen tried to figure out what he was saying, gave up. “What situation? What do you—”
“Our situation, here, Helen.” He looked up. “It’s not comfortable in here, but we can survive—as long as Zarathustra doesn’t suddenly decide to give up the ghost—for a long time. But Larry and Maddie—”
Oh, goddamn it. Joe didn’t have to spell it out. “They’ve got no real shelters, only whatever food their suits has in the units, and however much breathing their current charge can give them.”
He nodded. “Now, that’s not terribly limited—we all charged up prior to this cycle, and if Maddie doesn’t overdo things they might have a week or even two of air. But by that point the waste recycler will be full. Long and the short of it is that they’re the ones in trouble.”
“But Athena…” she trailed off.
“Yeah, Athena. That option was predicated on the—entirely reasonable—assumption that we’d all retreat inside Zarathustra and live in cramped but not impossible style for a few weeks while Athena bored down to our level.”
“Can’t they speed her up?” Helen realized just what horror they were contemplating. If the tunnel had collapsed, there was no way out.
“Some,” Joe admitted, “but I’m not sure that Athena could make a kilometer in that time even if they redline her and ignore all safety interlocks and protocols.
“No, the fact is, Maddie’s not going to be able to rescue us. We have to rescue her.”