by Hal Clement
And it would be fun to see what the depths of Habranha were like. Jan would already have some guesses, he knew; that was one of the things so wonderful about her. Comparing prediction with fact was always fun. Of course, the process might kill you, but that made it more interesting. There must be information on that old diving juice somewhere. A few minutes, or hours at most, in touch with practically any Erthuma world’s data bank should take care of that problem. That would be a highly worthwhile use of communicator and search program time. And it wouldn’t take very long to apply the knowledge in any workshop. You might even do it with the sled’s equipment—no, one would have to get back to Pwanpwan or up to the station. But one could do it. And maybe the atmospheric chaos on what should be a quiet, tide-locked planet did have its origin in the oceans.
Bill, least cynical of the five except for Janice, was reviewing his initial surprise that the star travelers hadn’t been into the deeps. He had taken for granted that his own planet, however unique and complex in detail, must be just another world to them, and that they had to have routines for studying planets. The thought that his home was unusual enough to make the routines inadequate was somehow pleasurable. There were things he and his colleagues could teach these strange, highly knowledgeable beings after all, in spite of the impression of their own superiority the winged aliens seemed so willing to share. He knew little about the wingless ones who had appeared more recently, but they too were star travelers, and no doubt felt superior because of that.
Bill was one of the few of his species who knew about stars other than Grendel’s companion sun Fafhir by more than hearsay. Most people stayed on, over, or under the ring-shaped continent on the daylight side of Habranha, which was continually adding to itself at about fifty degrees from the sun and melting away at about twenty, and this was in constant daylight. Fafnir was of course visible; its motions had provided the first observable no-fricton system, and had led to the development of physics, according to history. Other stars had been discovered only when researchers had learned how to travel briefly in the dark hemisphere; the nature of stars, until the arrival of the Crotonites, had been entirely speculative, and many Habranhans felt some doubt even now about their existence.
A few scientists had been tempted by the thought of traveling beyond the atmosphere, but those who had tried it had returned very quickly and unhappily. One could see well enough out there; it was fascinating to have theories about the shape of the world and the continent so easily supported. One could not, however, feel anything. Whether this was because there was nothing near enough to feel or because the strange material of the flying craft blocked electric fields so effectively could not be said; either way, the experience was highly claustrophobic. It was known that the aliens lacked electrical senses—they even had to transform normal speech into something else; maybe this was why they weren’t bothered by space travel. No one had been able to find out from the Crotonites; Bill wasn’t sure whether other alien species had been asked. There was a new one who actually flew only in water, he had heard . . .
It would be interesting to accompany an alien group into the deeps, if they could be persuaded to go—and if they had the technology to go; presumably deep-juice wouldn’t be any use to aliens—but maybe the stuff they made their ships out of could actually resist deep pressure . . .
He’d have to get back to the ring and ask some questions. It was unlikely, statistically, that there were enough aliens here to provide answers. No one knew everything.
The thoughts, even though shared with reluctance, could lead to only one course of action.
II. Below
He’d been right, Venzeer thought. It was dark, and the lack of stars was frightening. The lack of orientation was worse. Normally one could fly in clouds with due attention, but that was when the clouds were suspended in air and one’s weight and sense of speed meant something. Here, the effect of wing beats was different, and one couldn’t beat them very fast anyway, and one couldn’t sense speed through armor even if the impact sense had meant anything in water.
He couldn’t blame Rekchellet for spending most of his time in the living sphere of the Compromise. If he himself had had such a good excuse as the failure of the drawing pad to work underwater, he’d have used it. The fact there was little to draw was secondary; Rek was still busy making what records he could, though these were mostly words and figures from the instruments.
From where he was, Venzeer could see the new supply carrier of course; even the thought of going out of sight of it aroused—not panic, of course. Just plain, rational fear. There was no obvious way of finding it again in the starless dark. No way of finding any direction—not even up or down—with any confidence.
He could not quite see why the Erthumoi had wanted to name the vessel, since they had not bothered to name the sled, but he could agree with the name itself. It was a modified Habranhan mining sub, open to ocean pressure. Its hull was merely a polymer framework—metal was a laboratory curiosity to the Habras—to hold the mud tanks and engines. The natives had an interesting form of fusion-electric drive, the power conductors being extremely well shielded so as not to dazzle the crew’s other senses. The shielding was a conducting polymer, the natural electrical senses of the natives had led to a bypassing of one problem a growing civilization might have faced on a continent of ice.
The ship’s frame members were tubular, filled with heat-exchange fluid which could be pumped where needed. The ice in Habranha’s ocean depths had a sometimes inconveniently high melting point and could be found at surprising distances from Darkside.
Bill, Hugh, and Janice had been willing to spend a month or more in diving fluid and full-recycling armor, but the Crotonites had had to improvise brute-force protection and couldn’t stay in their suits continually. Hence the vessel now had two linked transparent pressure spheres near the center, replacing a pair of the original cargo tanks. One globe served as an air lock, the other as living space—very cramped living space, even at eight meters inside diameter, for anyone with wings. Even Rekchellet came out to fly around, without his pad, fairly often.
When the craft was traveling faster than any of them could fly, which was most of the time, people stayed inside the openwork hull and held on. If they had to rest, they used a cargo tank. Venzeer and Hugh had suggested, during the mission planning, that some of these receptacles should be ballasted with mud to conserve power which would otherwise be needed to force the buoyant living space downward, but the natives had declined. Irrigation mud, which made their continental ice fertile enough to grow food, was too valuable. When the Crotonite research center at Pwanpwan provided a few hundred tons of copper, the Habras had offered to trade mud for the metal, but Venzeer had declined. The metal slugs were easier to handle. He kept the peace by suggesting that the copper might be donated to a Habranhan laboratory after the trip.
This, of course, would be lengthy. Like the vehicle, the mission was a compromise between the needs and interests of the natives who had furnished the submarine and the alien researchers. The latter wanted not only to learn things about the planet but also in some cases to apply persuasion to its natives. Since not all the offworlders wanted to sell the same things, and none of them dared to say this openly, the final compromise was complex in detail and fully understood by few if any of the beings involved. It had, however, already brought the Compromise closer to the Solid Ocean of Darkside than the Habras had so far explored.
This was not because they hadn’t tried, Bill maintained, but because neither submarine nor free swimmer had ever, so far, returned from the region. There was no obvious reason for this; if anything, the undersea weather should be least violent there, since the descending vertical glacier was presumably quite pure water with no sediment and solute complications. He had told stories which confirmed Janice’s picture of silt and “snow,” violent currents in all directions, large icebergs and small, monsters and minibeasts. They had encountered some of these since leaving the
ring continent, but this had all been out in the warmer ocean. Venzeer doubted much of the rest since Bill had not seemed the least worried about going along himself. The Crotonite had quickly come to suspect that the native was trying to frighten aliens away from exploring in and under the sea, where by his standards the world’s wealth lay. This attitude was quite familiar to most Crotonites and not wholly unknown to the Erthumoi.
Bill was visible now, swimming calmly a few meters away. The lights from the Compromise showed him in silhouette, his wings moving languidly as he followed a tortuous path around the slowly moving vessel. He claimed to be making observations when he did this, testing with his own strange senses the temperature, density, and solutes of the ambient ocean, measurements which would all be compromised if made too close to the ship and its drivers. He certainly made records of some sort after each sortie, but not even the Crotonites could read these, and Venzeer retained his doubts.
Janice didn’t, of course. She had before starting calmly asked William to tell her everything he observed from the beginning of the trip on, and he appeared to be cooperating. She had accepted the fact that the mission was dangerous, and was seriously trying to decide what the danger might be. She was willing to take chances, especially since Hugh was along, but had no wish to be taken by surprise. She wanted to know the local rules as well and as quickly as possible.
While the information on the diving fluid was being sought, and later while the material was being manufactured, she had spent much communicator time getting library material on high-pressure phenomena, and memorizing a great deal of it. Of the five beings traveling in the middle of a bubble of light with, as far as they knew, over a hundred kilometers of crushing ocean in every direction, she was by far the most tense.
Hugh had enough sense to be afraid, but was nowhere near panic. The diving fluid, it had turned out, had been known and used for years, though not on his own world, in pressures approaching those of their present surroundings. There had been no trouble finding out about its nature, methods of manufacture, or the practical problems of its use-—which included finding or inventing, and learning to use, some form of nonverbal communication code.
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 casi
ngs, 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.”
