Complete Short Fiction, page 260
No one, apparently, had ever had occasion to use it under Habranhan bottom conditions nearly four hundred kilometers farther down, but for the moment there was no plan to go to such depths.
Rekchellet was the unhappiest. There was nothing to see except the craft he was riding and his fellow explorers. He had drawn all of these in as wide a range of situations as the surroundings afforded. He had records of ammonia content and temperature and suspended matter and even some information on currents, though these were as hard to check as gravity in free-fall. One did not draw this sort of thing, however; one wrote it.
Worse, there was no way to get their exact position, so even a map was out of the question. The natives lacked inertial trackers, and there had been none available at Pwanpwan—not because none existed, but the Crotonites and others studying the motions of the ice which made up Habranha’s ring-shaped continent had firmly refused to loan any to a high-risk expedition. Rekchellet knew he should have done the arguing instead of letting Janice try, but he was coming to regard her more and more as a being, not just a ground crawler.
He had records, but all in numbers. He had tried graphing the information, thus turning it into pictures of a sort, but was disappointed by the results. Compromise was at the depth where water had its lowest freezing temperature, about twenty kelvins below what everyone in the group considered normal, so his graph suggested that they were moving into a cavern with ordinary ice above and a high-pressure form below. This wasn’t really a map, though. It didn’t mean they were actually in a cavern, still less that they were about to be crushed by falling or rising ice. For one thing, the ice above would float and that below would sink. The natives knew something about high-pressure ice phases. Even the Erthumoi, at least the female one, did. The glacier on the ocean bottom, crawling its way back toward Sunside after centuries of travel from the Darkside snow sheet down hundreds of kilometers of Solid Ocean column, was what Janice called ice five, and they were currently at the pressure boundary between ice one and ice three, a hundred and fifteen kilometers or so below atmosphere.
The trouble was, one didn’t know exactly. Pressure gages did not have four-digit accuracy in this range. Bill’s senses didn’t reach. Sonic measures were wholly unreliable because of the vast reflecting, scattering, and absorbing layers of silt and plankton and the labyrinth of thermal currents. The globe of light which let Rekchellet see a few score meters around the Compromise was a prison, and the transparent living shell where he spent most of his time was a closer one. Flying was necessary now and then, but wasn’t much of a relief. It wasn’t really flying—not when Erthumoi could do it even with their ridiculous limbs. The artificial flippers of negligible area they wore on their walking appendages didn’t count. Rekchellet felt annoyed and frustrated.
William was happy. He was doing something new and useful in a field he had enjoyed all his life. Like Hugh, he was intelligent enough to be afraid, but like the man he was able to face the danger philosophically. He was the calmest of the group, predictably; the situation was more familiar to him than to any of the others.
He was therefore less alert than Janice. The only reason he perceived the menace first was because it affected something familiar to him.
He noticed suddenly that it was harder to move his wings.
At almost the same instant, he became aware of charge building up at the joints of his armor, except the wing hinges where there was constant motion. He was an experienced diver, and almost reflexively moved his handling limbs and bent his body to test the other joints. The growing charge disappeared at each one as it bent; he could sense the current which flowed briefly as charge neutralized. He also detected a faint grating sensation, as though some fine powder were in the joints. He wasted no more time but flapped hastily toward the Compromise, calling a warning.
“Venzeer! Hugh! Janice! Come in quickly!”
The Erthuma couple obeyed without question. Venzeer turned toward the craft, saw nothing wrong, and called, “What’s the trouble? What have you spotted?”
“Ice, I think. Do your wings move freely?”
“They never have, down here. I don’t feel anything worse than usual.”
“Come in anyway while we check. Rek, read the thermometer.”
The artist glanced at the instrument console and called out a figure which the Erthuma listeners heard as “two-forty-nine.”
Janice compared this with the phase figures she had memorized, and thought, That’s two kelvins below pure water’s freezing at this pressure. The water’s a long way from pure, though; there should be a good deal of ammonia and lots of other solutes. There shouldn’t be ice yet. She could not talk, of course, with diving fluid in her vocal cords, but keyed a terse “Why?” on her code transmitter.
“Everyone get inside first, and we’ll talk theory later,” snapped the native. “If snowballs grow, we want to all be in the same one.”
“There is something fogging the hull,” reported Rekchellet. “I can’t see any of you clearly now. Venz, I can’t see you at all. Where are you?”
“Level, about sixty meters, almost straight behind. I’m coming in—but it is getting harder to move my wings. Better slow the ship or stop it till I get there.”
“All right. Hugh? William? Janice? Are you making it in all right?”
“I’m here and inside, clamped on,” came the native’s voice.
“Ten meters,” keyed Hugh. “No trouble. Swimming easy.”
“Any seeing trouble?” asked Rekchellet.
“Just bad light.”
“There’s frost growing on the finer hull members,” Bill announced. “I can’t make out the type; the crystals are growing fast and aren’t large enough to identify. All of you look around for parts of the ship which would be slow to cool; larger structural members, engine casings, and so on. If any of you can tell whether we’re getting hexagonal frost or some other kind, let me know at once!”
“Why?” tapped Hugh. “Why not find warmer water? Near glacier anyway?”
“It matters—” The Habranhan’s voice was interrupted.
“I’m still ten meters away and can hardly move my wings at all,” Venzeer cut in. “I seem to be heavier, too. It’s all I can do to keep level with the ship. There’s white stuff all over my wings, getting thicker as I watch.”
“Never mind the crystals report,” the native responded instantly. “It’s middle ice. We’ll have to go up to get rid of it, but not too far or we’ll have low ice instead. It’s growing on the ship, too. Rekchellet, steer back so we can pick up Venzeer and get him aboard before he sinks out of reach. I’m not near the main controls. If we have to follow him down the ice will get thicker and heavier as the pressure rises, and we may not be able to get out ourselves.”
“But I can’t see out, now. How do I pick him up?”
“No ice on us. We’ll help.” It was Hugh’s coder again. “What goes on? You sound informed, but never warned us.”
“First things first. Rek, shift to slow ahead, and turn—left is better. Good. Nose up a little; you’re starting a dive—not very steeply, but any is too much unless we really have to go down after Venz. That’s good. Hugh, I can’t sense very far now either; frost is forming on the lights, and charge on the body is confusing. Are you near him yet?”
“Here, holding wing—”
“I have the other,” Janice cut in. “Keep turning. There. Straight. Straight. A little right. Straight. Tiny down. We’re sinking. Almost—farther—there. I have hold of frame. Wings frozen open, further aft to get inside. Wait. Now. Safe.”
“You’re inside? All right. Rekchellet, work us upward, very slowly. With luck, which means if we aren’t too close to Solid Ocean, that will get rid of the frost. Just start the maneuver; I’ll be forward in a moment and will take over control.”
“Why up? What happened? Explain!” Hugh sounded emphatic even by code. Bill answered with apparent calm.
“I’m not sure I’m right. I said we’d need luck. There are several kinds of ice. I have control now, Rek. What we find on and near the surface is less dense than liquid water, so it floats. That’s ordinary land. I should say it floats if it doesn’t have too much mud in it, and it’s land if it has enough. At middle depths we find another kind, and very far down a third. The last kind is very hard to melt at the greatest depths, and both are denser than liquid water.
“We are near the depth boundary between the first two kinds, and I needed to know which was forming so I could tell whether we needed to go up or down. If it had been high ice and we had gone up, the decreasing pressure would have raised its melting point and we would have accumulated more and more, and finally reached the surface, or more likely hit the bottom of the surface pack, in the middle of a fair-sized iceberg with no way to get out, since we wouldn’t have been able to move. Us, not just the ship. If it had been middle ice, and we had gone down, the increase of pressure would have raised its melting point and again we would have formed the center of a large berg, this time on the bottom or on the deep ice shelf, if it exits. It ought to, since ice gets ‘way out toward the ring on the bottom. Before we got there, the change of the stuff around us to deep ice would have torn ship and us apart as the volume changed in different places at different times.
“When Venzeer said he was being dragged down, I judged it was middle ice, so I am sending us up. The decreasing pressure should lower the melting point and free us fairly soon.”
“Unless we overshoot,” Hugh suggested. “Phase boundary. Right?”
“Quite right,” Bill replied calmly. “I thought it was Janice who had all that information.”
“She has the numbers. I’m like Rek—just pictures.”
Janice’s code tone came in. “Ice seems to be going.”
Venzeer confirmed this with glee. “I can see my wing tips again.”
“Can you move wings?” Hugh asked, practically.
“Not yet. Better keep hold of me.” The Crotonite had a grip of sorts on a part of the ship with his handling nippers, which had not been as solidly immobilized as the great wings, but his rescuers had been carefully supporting him against the currents which rippled through the openwork hull of the Compromise.
“Don’t worry,” Janice assured him. “You’re thawing. Why no ice on Hugh and me?”
“Your armor’s at higher temperature,” Bill pointed out. “I don’t suppose you generate as much body heat as we flyers, but with no wings you have a lot less surface area for dumping it.”
Of course. Simple physics, thought Hugh to himself. Much simpler than the phase behavior of water. Aloud he coded, “Jan, how about solvents? Ammonia practically everywhere—”
“Not here,” Bill interrupted. “I’ve never known such pure water outside a lab. There’s some life, but even the microbes must be hungry. What do we do now? I’ve backtracked our course for a kilometer or so, and it’s a little warmer, so we should be rid of the ice pretty soon—I should think you could see out now, Rek.”
“There’s nothing to see but the rest of the ship, but you seem to be right. I never got a sight of Venz with his wings frozen. How do we get a record?”
“You could come out and take a look before he loosens up, if you think it’s that important. The Erthumoi were never bothered, so it’s safe enough.”
“I saw. I’ll make a sketch for you later,” tapped Janice.
Bill remained concerned with their main task. “If we can’t get any farther and still make measurements, what becomes of the mission?”
“Plenty of power,” Hugh pointed out. “Warm ship?”
“My first thought is that it would invalidate any measurements we made,” the Habra responded slowly.
“Not much more than our mere presence does. Our bodies were losing heat to the ocean, too,” Venzeer pointed out. “Mine, especially. We need use only just enough heat to keep the frost off.”
“But that will leave a trail of warmed water behind us as we go along. It takes very little temperature change to start convective instability. That’s why computing weather even in air is so hard.”
“In air,” Hugh emphasized. “PV small in liquid. Expansion a lot less. Density change—”
“You may be right, but we get more violent storms in the deeps than in atmosphere,” Bill pointed out. “And this might be just the thing to start them. I’m willing to try it if the rest of you are, though. Just be sure we keep track of how much energy goes into the heaters. Computing a storm pattern is hard enough even with all the data.”
“Computation impossible,” Janice keyed. “Situation chaotic.”
“Nothing’s basically impossible,” replied the native, “but I grant it’s far beyond our present abilities.”
“Impossible,” the woman repeated. “Meteorology should have given you folks chaos theory. Maybe bowling alleys needed too. But let’s go. Solid Ocean should be near.”
“Why?” asked Rekchellet. “We don’t have any surface data. The upper glacier extends a lot farther into Sunside than the Solid Ocean—after all, the latter’s just a theory we’re testing—but no one knows how much, and even if we did we don’t know how far we’ve come under the upper ice pack. I know there’s a sonic reflection from what seems to be a more or less vertical surface somewhere ahead, but I wouldn’t guarantee whether it’s one kilo or fifty, or even that it’s solid. What’s the basis of your guess?”
“Water purity. Bill said it. Should be fresh melt.”
“That sounds reasonable,” the native agreed. “We winged folk had better stay near or in the ship. You others don’t ice up so easily and can fly ahead, making measurements as you go. Don’t get very far, though. Instabilities may always be possible to calculate, whatever your chaos theory says, but I certainly can’t always do them in my head, and I’m not at all sure I’ll be able to sense them. I got caught only a few minutes ago, remember.”
“But you weren’t thinking about that!” objected Rekchellet.
“I should have been. The point is that this is research, and if we knew what was likely to happen there’d be no point in being here at all. Be very careful, wingless people. I know you can fly here but can’t believe those limbs are really efficient. I would advise using safety lines; we have them aboard, you know.”
“How long?” asked Hugh.
“About two hundred meters. You wouldn’t want to get even that far, since the ship’s light won’t suffice for clear sight at such a distance and that’s your only useful sense.”
“We have lights,” Hugh pointed out.
“By all means. Use them. But I’d still use the lines and let them dictate how far you got. Here—make fast.”
Man and wife obeyed, since they were sensible beings. The Compromise resumed her cruise away from Under the Sun at very low speed, the Erthumoi swimming ahead. Bill was still in the control cage guiding the vessel. Rekchellet carefully saved each sketch he made of the team members blurring out of sight ahead and slightly to each side—if they had gone straight ahead, the mud tanks forward of the living sphere and controls would have hidden them from everyone’s sight, though perhaps not from the Habra’s electrical senses. All the Crotonite could see were portions of the two safety lines, which had been made fast not to the bow but to frame members close to the pressure spheres.
The advance party stayed in code touch as well; sound, even the code, carried well through the water, and all the suits except Bill’s had impedance-matching coatings to handle the interface problem. The native had his own sound-to-radio transformer, and had learned the code during the weeks the Compromise was being rebuilt. For some time, the only words from the advance scouts were the routine “nothing new.” Bill stated with equal regularity that the water was still very pure.
Then Janice’s code came back off schedule. “Turbulence! Watch it, Hugh and Bill. Almost snapped my line.”
“Nothing here,” came her husband’s response. “You did—no. Just local I—” His code ceased.
“Why local?” came Janice.
“Don’t know. Maybe—” The Crotonites were irritated by the confused symbols, though they realized the cause. Bill forestalled any complaints they might have uttered.
“Not time to theorize yet!” called the native. “Come back toward the ship. Stay only ten meters or so ahead, so you can give me warning but will be able to come in quickly and hold on if something bigger hits.”
“Can’t you sense them?” asked Hugh. “No. The water’s too clean and featureless—I could spot something distorting the heat ripples of your suits when the eddies hit you, but no sooner. Stay close. I’m feeling turbulence with the ship, now.”
“Me, too,” asserted Rekchellet. “It’s good. I haven’t flown a cumulus cloud in months.”
“It won’t be good if it puts too much bending stress on the ship,” the native replied grimly. “I’m feeling it more now. You Erthumoi get aboard fast. I’ve been in lots worse storms than this seems to be so far, but not with crew outside—and then I could usually tell what was coming.” Janice and Hugh obeyed without question. The Habra went on, “I assume we still go ahead. Rek, get everything you can tell from your instruments on record. Never mind drawing, you can write. Just keep notes, and save them. We’re—”
“Jan! Slack!” the man’s code interrupted the pilot’s orders. “Bill! Sharp right!”
Hugh and his wife had obeyed the original command to pull back toward the Compromise, and had been some twenty meters ahead. The woman was about as far to the left of the vessel’s bow; Hugh on the other side. Something had suddenly become visible: a white, very thin and twisting tornadolike funnel reaching from the darkness ahead. Before this actually got to them, something snatched Janice forward, to the right, and somewhat downward. Hugh reached for her, but she passed a dozen meters beyond his grasp. Both had coiled their lines as they came in, but the woman had been slower, and had been startled by the sudden jerk of the current. Some loops of her coil escaped her grasp.
