by Hal Clement
“Are all the faults running north and south?” asked Belvew.
“Just about. Maybe I’d better land and get Maria off the ground while there’s ground left.”
“There’s no hurry about that,” insisted the commander. “You can’t land in this fog; it’ll have to be down by the lake as usual, and there’s no point in doing it at all until I’m nearly there. Besides, I need to look at the pool—how about more samples from there, right now, Cheru? Or have you been keeping track already?”
“There are lots of samples analyzed and filed,” was the answer. “I don’t know the details myself; I’ve been doing them, not thinking about them.”
“Status?”
“There has been a steady increase of complex organics in the pool. Material from Commander Goodell’s body seems to have been diffusing at a rate much higher than the temperature would render likely. Whether this can be the cause of the color change is uncertain; the two rates do not match at all closely.”
If any of the group felt discomfort at this calm report, none made it audible. Maria thought a moment before speaking.
“We have labs at the other pool here in the crater. Do they show anything similar?”
“No. No change.”
“How about the ones near the factory—the one here?”
“Small changes, so far of no apparent significance.”
“Anything interesting from the seismic net?”
“Yes. There seems to be a body of liquid below the crater, about three times its horizontal area at the widest, top at a depth of fifty-three kilometers, bottom about one hundred fifty.”
“Maria, get out of there! Get off the ground! That’s got to be a magma plume!”
“More likely water, Gene. Are you asking Ginger to land beside me in this fog?”
“Well, no. But hurry down to the lake, and water is magma here!”
“The commander has eighteen point five hours before emergency status,” the processor interjected.
“So who’s worrying about your suit?” snapped Belvew. “That crater’s trying to become a volcano. Eighteen hours could see its floor all cut up with faults or covered with fog so no one could land anywhere anyway.”
“Is any sort of prediction possible, Status?” Maria was not nearly as calm as she tried to keep her voice.
“Not from present data. The liquid may be the source of the fog, but I have found no trace of a feed from the depths to either of the fog sources. The probability that both the fog and the liquid are water seems high, in spite of the lack of ice crystal structure in the former.”
“I can make a guess at that,” Akagewa cut in. “The gas coming out of that crack is mostly nitrogen, with a healthy trace of methane. Its temperature at the height where the lab is bobbing is about a hundred and ten. I suggest the white stuff is water, supercooled on the way up from the magma chamber, showing no crystal structure either because it cooled so fast it’s a glass, or because the drops are so small surface tension keeps them liquid. Either would explain the lack of structure.”
“Maybe it would explain something else,” the commander put in, using a tone that bothered Belvew.
“What’s that?”
“I’ve just been knocked down by another shock—”
“Why didn’t you tell us, or at least Status?”
“Because it’s becoming routine. I landed on my back as usual, and this time rolled over to push up with my hands instead of my elbows. The white stuff is sticking to the front of my armor, I see; and I think it must have been sticking to the back for quite a while. That part has been feeling surprisingly warm for the last half hour or more. I can’t see or reach my back but I bet it’s there, too, and is not only acting as insulation but providing heat as it freezes.”
“Why should it freeze?” asked Martucci.
“Loss of spherical shape would drop the surface tension and the pressure. Ask Gene why rime ice forms on wings. If I’m right, I’m pretty well covered by the stuff now. At least it’s not interfering with my walking.”
“It’s interfering with something else.”
“What’s that, Pete?”
“I can’t see you any more—at least, I can’t distinguish you from the rest of the white stuff. I hope you’re still having no trouble with your trail.”
Maria made no answer to this, but gave an order which Belvew interpreted as one.
“Ginger, get down to one hundred meters and circle over the area where I should be. Look for me as carefully as you can without risking the jet with low speed. Call out if and when you see me. I’ll keep moving, which should help.”
“Does that mean you can’t see your back trail?” asked Belvew.
“I can see it, but not as far back as before.”
“Is the fog getting thicker?”
“I can’t tell. There’s nothing but the trail that shows at all in this white stuff. It may be heavier fog or faster filling in of my tracks or some of both.”
“Then travel! Get as far as you can as fast as you can! Try to get out of the fog before you lose orientation entirely.”
“That’s what I’m doing. But there’s a limit to my speed, remember. If I try to run, I automatically jump, and if I jump there’s a very good chance I don’t land on my feet. That doesn’t help speed.
“I hear you, Ginger. You’re almost overhead . . . I caught a glimpse of you; this stuff can’t be as dense as it looks. You went not quite overhead. I was a little on your right.”
“How long was that before you spoke?”
“Two or three seconds after I reported hearing you I caught the glimpse.”
“Good. I’ll be coming back over that point in sixty seconds from—NOW. I’ll be heading straight toward the lake.”
“You can still see that? The fog hasn’t blown over it yet?”
“Not enough to hide it. I’m turning. Can you still hear me?”
“Yes. Lucky this isn’t Earth; in a blizzard like this the wind would never let me hear anything else.”
“On Earth we wouldn’t be this worried about you,” snapped Belvew.
“In a blizzard? You’d better read about Scott and Shackleton. Even Earth isn’t always a really nice place. Ginger, you’re coming—THERE! Right overhead!”
“Good. You’re only about thirteen hundred meters from the lake, and should be able to see your way in six or seven hundred. Can you hold your heading now? Should I go back to filling in geography-time derivatives for Status, or would it be best to keep near you and give you direction every minute or two?”
“Work on the data.” Maria spoke firmly, but not loudly enough to drown out the start of an answer from Gene. He failed to complete the first word, but no one doubted its general flavor.
“All right.” The roar of the ramjets faded, and Maria resumed her hike. Her suit was beginning to feel a little stiff, presumably because of the accumulation of whatever-it-was at the joints. She turned her mind firmly from that phenomenon, and asked Status to update her on seismic information as she walked.
“There has been no major change, though finer details are being added. The new can lines are providing much data in spite of their spacing. The magma or water reservoir is as I described it before. I can now trace the crack which is feeding gas to the vent line you examined. Six more such faults exist, outlining a prism of crater floor, but have not yet reached the surface. Practically all the activity is under the crater; it may be that the impact itself has some connection with what is going on.”
“That would suggest that it’s very recent,” Maria commented.
“Quite possibly. However, there is little difference in the average thickness of the smog sediment inside and out, so either the crater is quite old or the general surface is being reworked much faster than we thought.”
“Status,” Gene cut in, “tell us more about those six feeder faults. Where are they? Are they changing—getting any closer to the surface?”
“They are much shorter than any of
the others. They intersect to frame the lake and immediately surrounding area in a rough hexagon or, in three dimensions, to place it at the top of a rough prism. I can give you precise coordinates if you wish. They are extending fairly rapidly, and will reach the surface in approximately eight hours at their present upward rate. I cannot tell which side of the resulting faults will be the higher; I have no reliable way to infer stresses from the behavior of the seismic waves.”
“But there’s a good chance that the whole lake area will lift up on a six-sided platform in the next few hours.”
“Or sink. A chance, certainly. It would not be a reliable prediction.”
“What would that do to available landing space?”
“That is already decreasing, assuming a six hundred meter landing slide. If the faults I have just reported reach the surface it will be necessary to land further to the south than before, if we continue to do so east and west. Any other run direction would have to be farther from the lake.”
“And from the Commander?”
“Yes.”
“Hear that, Maria?”
“Of course I heard it. I’m hurrying. I still think it’s important to get a good look at Arthur’s Pool.”
“Do it from the air! Get out of that crater as fast as you can!”
“As long as I’m heading near it anyway, let’s not argue. I assume, Status, that the tunnel is no longer of primary importance. How about the general plan to move to the surface?”
“That will have to be dropped until a new settlement site is found. The crater is now unsuitable.”
“And Arthur’s—uh—experiment is wasted?” asked Ginger.
“Not necessarily. His pool is well supplied with labs, and we can keep track of what happens there unless it and they are all destroyed. Even that could be informative.”
“Then I should land as close as possible to that spot.”
“Not until I get there and tell you to!” snapped Maria. “The jet is less expendable than I am, right now, and you know it.”
“I know it, but I don’t believe it. Are you able to see any better yet?”
“A little. I’m having to move more slowly, though; the knees of this suit are getting stiff. I suppose no one can see me yet; I must be pretty well covered with this stuff, and there still aren’t any bare spots I could stand on for contrast.”
“I’ll come back and make another pass. You should be getting out of that cloud by this time. There; I’m heading where you ought to be. Can you hear me?”
“Not yet. Where are you?”
“Just crossing the south rim, inbound,” answered Ginger. “Half a minute should bring me about over you. I’m at standard.”
The commander waited briefly. She heard the jet in a few seconds, looked up in the hope of seeing it, and just barely succeeded.
“You’re a couple of hundred meters off to your right—NOW!”
“You haven’t held course, Maria. How about using the wind? It’s still from the west, and you can see the stuff blowing.”
“Too turbulent to be useful, as least close to the ground. I’d thought of that. Getting knocked off my feet, and I suppose picking up more covering, every few minutes doesn’t help.”
“You know where she is. Pick her up now!” cried Belvew.
“Stop thinking of that!” Maria had never sounded so much like a commander. “Make another pass over me, or as nearly over me as you can, Ginger, heading as straight as you can for Arthur’s Pool. You can still see it, can’t you?”
“Sure. All right, coming back. Call when I’m closest, and tell me which side you’re on and how far if you can. I’ll be a minute or so with the turn. All right?”
“All right?”
“ALL RIGHT?”
Maria couldn’t answer. She was off the ground again, totally disoriented. She snapped both hands above her helmet to protect it in case she landed head downward, and ignored Ginger’s increasingly frantic calls until she struck the surface again.
Her heels touched first, with her body extending back and up at about forty-five degrees. On Earth she would have slammed down on the back of her helmet; on Titan the rest of the fall took well over a second and she had plenty of time to spin cat-style and land on her hands. A medium hard one-handed push-up brought her back on her feet; she felt a fleeting glow of pride that she hadn’t overdone it—much. One short backward step kept her from falling the other way.
“I’m all right. I got tossed around by another quake. I don’t know whether you passed me then or not.”
“I must have. I’m half way to the rim—Maria! My Aitoff shows a new cloud erupting all around the lake! Is it blocking your sight?”
“The eight hour prediction was inaccurate,” Status interrupted, “but the qualitative extrapolation offered by Sergeant Belvew was very good. The lake is now near the north rim of a hexagonal area well marked by fume-emitting faults. It will take a minute or more to determine the new height of the area. The lake itself has shown no significant change in shape or area. If Major Xalco will try again to locate the commander—”
“Is that area big enough for landing?”
“Is the Pool inside the prism?” came Belvew’s and Maria’s interruptions simultaneously. Status untangled the sound patters, though none of the human listeners could. The processor answered the commander first.
“The pool is inside the area described, though quite close to the northwest corner. It has not been visibly affected by the shock. It should be possible with care to land the jet within the hexagon. I would advise landing westward, touching down as near the east corner as the pilot’s skill permits.”
“Take it, Gene,” Ginger called promptly.
“Not yet. Finish your run. We need to know whether Maria’s inside the hexagon, too. It she isn’t, and the boundary is hard to cross for any reason—remember how she got blown into the air at the other place—we don’t want to land there.”
“Right. Give me the call, Maria, if and when. Here I should be coming.”
“I hear you but can’t see you. The fog’s a lot thicker, I’m afraid.”
“Not even a glimpse?”
“No.”
“Any guess at the direction of my sound?”
“Not in armor.”
“Shall I make another pass?”
“No use, I’d say. If the new fog allows, you might go as low as seems safe over the hexagon and help Status find out if it’s higher or lower than the rest of the floor. I’d guess it had dropped, or rather that the outside rose—I was tossed upward again.”
“You’re assuming you’re outside.”
“Yes, Gene. Unless my earlier position was wildly off or I got tossed several hundred meters, I have to be north of it still.”
“I suppose so. All right, just go on, I guess. You can see your track still, can’t you?”
“As a matter of fact, no. The snow seems to have been tossed up, too, I’m afraid.”
Not even Status had an immediate answer for this. After some seconds, Belvew asked, “Can you see the tracks you make right now—after the shock.”
Maria experimented—the answer seemed obvious, but she was taking no chances on another trivial surprise—and answered affirmatively.
“All right, just start walking, and keep a straight line as you did before, I’d say. If you’re lucky and get into clear air, fine. Sooner or later you’ll have moved far enough so Ginger can get some idea of distance and direction from when you can hear her pass over, even if that doesn’t give much resolving power. Can anyone think of anything quicker? Staying put certainly won’t accomplish anything.”
Maria admitted this, and decided not to mention that the joints of her armor were getting stiffer. There would be time enough for the others to face that worry if and when she were actually immobilized. It would have been nice, she reflected as she started to walk, if she had had a rope, or a few meters of wire, or something like that to drag behind her. Even if that were tossed off the grou
nd, it would have to fall back somewhere near its original position.
Theia boomed overhead, and the commander reported the sound as soon as it started to fade. Two minutes later she heard it again, this time with a fainter maximum, and she passed on this information as well. The third time was fainter still.
“All right, I think I have you fairly well pin-pointed,” came Belvew’s voice—he had evidently taken over the jet. “Just keep travelling, and report any sort of change you catch. You’re about where we thought, only a few hundred meters from the nearest of the new faults.”
“You said they were putting out fog, too. I can’t see any difference in the vision range yet—of course, I don’t really have any idea of how far I’m seeing. I think I hear something besides the jet, though.”
“What?”
“It’s like the deep whistle of the stuff coming from that other fault, but that may not be objective. Keep your fingers crossed, those of you who aren’t flying. I’m still walking.” The last statement was not a complete truth; her armor was continuing to get stiffer, and the walk becoming a totter.
Twice more in the next few minutes she was thrown from her feet, but neither time was her track too badly smeared. The escaping vapor, if that’s what it was, grew louder; she had trouble hearing the jet at all when Belvew made another attempt to locate her, but they both felt sure she was approaching the nearest edge of the hexagon.
She was. A scarp loomed suddenly in front of Maria just as she was seriously wondering whether she would have to report her travel problems—and also wondering what good the report would do. It was only a dozen meters away; the fog was far thicker than before.
“No wonder I was tossed around, even if the prism went up more than I did. Your hexagon is over two meters above the rest of the floor, at least on this side,” she reported. “I wonder whether this is something common here, or whether Arthur just picked a very bad spot.”
“It will take a lengthy review of the worldwide mapping records to tell,” Status replied. “Nothing of this sort came to anyone’s attention earlier, and I was instructed to test for albedo changes, not heights.”
“You can get up on the new level and check Arthur’s Pool in a few minutes,” Belvew said happily. “I can’t be sure where you hit the edge, but it almost has to be the north face. The pool could be about in front of you, or anywhere up to three or four hundred meters to your right. You’d know it, I suppose, if you were right at a comer.”