Still River

Chapter Seventeen Of Course We’ll Wait

“You mean you moved away from it without noticing? How could that happen?” asked Jenny.

“We mean the river is gone,” stated Carol. “So is the only wall we could see, and so is the ground under us.”

“Stop and backtrack,” said Joe quietly.

“Right. We are. I’m driving much more slowly just to play safe, but—yes. There it is again. The way we were following simply opened into a much larger cave, like the one above. The river is tumbling in through the ceiling; it looks really weird in this gravity.”

“It could still pack momentum,” remarked the Nethneen. “Be careful.”

“Don’t worry. The wind around it is plenty of warning, slow as the waterfall looks.”

“Which way is the wind? Any guidance?” asked Charley.

" ’Fraid not,” replied the Human. “Random stuff; eddies set up by the moving water. We’re holding motionless, if the inertial guidance can be trusted, and can feel this-way-that-way gusts trying to knock us off the robot.”

“Then what will you do? Come back the same way you’ve been traveling?”

“Where would that get us? And when?”

“Closer to the surface, at least.”

“Not good enough. All we know about the area around the original cave is your information that there seem to be no other surface openings near it. At least it seems sensible to be heading somewhere else—maybe toward one of the places you or Jenny have found. Heading down a river has something to be said for it, by itself; if any of you find one, doing the same is probably the best remaining chance of getting us together.”

“If rivers tend to converge underground the way they do on a surface,” Charley remarked.

“Do your own theorizing about that; I don’t want to!” snapped the Shervah.

“You could be heading straight away from the region we’re mapping.”

“Maybe,” agreed Molly. “This robot knows somewhere inside its crystal cerebrum, I suppose, but we can’t ask it. Or maybe—Carrie, you’ve been using the inertial system telling this thing which way to go. It must have some reference direction of its own. If we let it sit quietly on a solid surface, how long would it take to tell itself, if it doesn’t know already, which way and how fast this planet is rotating? Personally I’d guess about five minutes, but you know better than I do, probably.”

“I’m not sure I do, but that seems a reasonable guess. Joe, I never knew—did you build the sensors in Classroom’s shop, or use standard ready-made ones?”

“Oh, I built them, of course. Slowly as Enigma rotates, five minutes will change attitude quite enough to measure. A good thought, Molly.”

“Then we’ll land beside the waterfall and let this thing decide which way is north, and then head in that general direction; that’s where you two have been finding your wind vents, isn’t it?”

“Yes,” replied the Rimmore. “Should we bother to look for more?”

“Of course. Keep on mapping toward us, if the storm will let you.”

“I have another suggestion” came Charley’s voice.

“What is it, Charley?” Molly answered quickly, gesturing her small companion to silence.

“I propose to go underground at the nearest entrance I’ve found; perhaps Jenny might do the same thing, but if she wants to do that she should use one of the places near where I do.”

“Why?” asked Carol impatiently, ignoring Molly’s obvious wishes.

“You can program the robot to stop after it has gone a certain distance in a certain direction—it can keep track of all components of its travel, no matter how irregular its actual path. Even if it won’t give any other signal, you can find out when you’re close to this area, which is…” he paused to interpret instruments “—three hundred fifty-one kilometers distant and twenty grads right of north from the hole you two went inside by. Just arrange for it to go that far in that direction and stop. It won’t be exact, obviously, but it will put you somewhere in this neighborhood. While you’re making that trip, I, and Jenny if she wants, can be mapping the caverns under this area, within whatever radius seems smart, and as deep as we have time for. We will, of course, file the map in the boat’s computer—no, we’ll be out of electromagnetic touch once we’re very far underground, but our own machines have enough capacity to record the planet, probably.

“Once you two know you’re in the area, you can start examining it in detail, moving around as seems good to you, and describing it carefully. Sooner or later we’ll find a match with one of our maps.”

“Beautiful!” Molly made no attempt to hide her enthusiasm.

Carol didn’t feel as happy, considering the source of the idea, but could not deny that it seemed a good one. “I’m not sure it’s better than staying with the river, but it has possibilities,” she admitted.

“There was a good windy cave only fifteen kilometers from here,” Charley resumed. “That will make it three hundred sixty kilometers and almost exactly north for your robot setting, Carol. Are you going to come over and map, too, Jenny?”

“Yes, by all means. Let’s see—my unit has copied from yours, so the maps are joined—there’s another vent only a dozen kilometers from yours, just about east—that will make its distance about the same for Carol and Molly, and we’ll be a broader target laterally. I’ll start at that one, and we’ll try to make our underground maps join up as quickly as possible at as many depths as we can.”

“Fine.” The Kantrick was in top spirits again. “I’m at the vent, and going underground. At least I’ll be out of the glare of this murderous star.” He shifted to private channel. “Was that the right idea, Molly?”

The Human couldn’t quite see the point, either of the question itself or of his making it private, but she followed his lead. “There are probably hundreds, almost certainly dozens, of workable ideas. This seems a good one. There’s only one thing that would make one ’right’.”

“Is it the one one of us was supposed to have?”

“Supposed by whom? I was hoping someone would think of something to get us out of this mess, and I’m happier than I’ve been for—it seems like weeks. Thanks, Charley.”

“Molly.” It was Carol, on general channel. The larger woman looked inquiringly at her. “I’d like to go fast, once we know which way to go, but I don’t want to sail at full clip through an empty cave with no idea of when the far wall may come up. Shouldn’t we find the bottom, if only to keep ourselves conscious of how fast we’re going and a little more alert to what may be ahead?”

“Probably we should. But how fast do we dare go down?”

“That’s no problem. The robot can sense its own height even if it can’t tell us, and I can key it to stop on a downward trip before it hits anything.” Carol refrained from mentioning how nice it would have been had the machine possessed similar horizontal sensing capacities. “As soon as we’re oriented we’ll move out far enough from the fall to feel safe, and I’ll set up a fastest-downward.”

“What if we’re over another lake? This waterfall—excuse me, you know what I mean—must stop somewhere, and…”

“It will read that as a surface. Don’t worry. Even if we splash, we’re in armor.”

Minutes later, the two were once more descending through Enigma’s darkness. Molly had set her light to the narrowest, brightest beam possible without hurting Carol’s eyes and was keeping track of the falling liquid a couple of hundred meters away, while the Shervah swept hers in the opposite direction and occasionally downward, using a broader focus.

“We’ll have to be ready to move farther from the fall,” the Human reported after a minute or two. “I suppose this is what happens to real water under decent gravity, too, but I’ve just never observed the detail. The fall reaches terminal velocity for this gravity and air density, which is pretty slow, and starts to break up into big drops, and those are blowing around randomly. I suppose they correspond to the spray under a real waterfall.”

“How big are the drops?” Joe asked with interest.

“The smallest I see from here are a centimeter or two. They range up to blobs of a couple of meters, changing shape and orientation as they fall—if you can call that drift a fall. We’re going down faster than all but the very biggest, so I haven’t been able to follow any one of them for very long. They’re pretty, Carol; have a look. I’ll cut my light for a moment; yours should reach that far, with your eyesight.”

The Shervah, unfortunately, followed the suggestion, and like her friend found the sight interesting. The drifting, shimmering, writhing blobs of fluid were indeed beautiful. Lacking cameras, they alternated with each other trying to describe what they saw to Jenny and the others. Not quite all their attention was thus employed—both were conscious that the “drops” were spreading farther and farther from the original fall and closer and closer to the robot, in their random wanderings—but neither was thinking of danger for the moment. Probably neither would have been able to foresee its details even with full attention.

Quite abruptly, the robot’s descent stopped, or seemed to. Carol reached for the control keys, while Molly swept her light around to see whether they had reached a solid cave floor or a lake. She saw neither, and before Carol could finish her key work the descent resumed. The Human began to report the event to the others, while her companion swiftly considered possibilities. A likely one occurred to her immediately. A large drop might have drifted below them temporarily and been interpreted by the robot’s sensor as ground. She suggested this to Molly, who interrupted her partially completed report with a brief “Wait a minute,” and both turned their lights downward to check the possibility.

It seemed likely enough; there was a blob of ammonia only a meter or two below, whose motion suggested that it might have been right under them a few seconds earlier. Molly nodded and was about to resume her call to the others when Carol called her attention to another.

“Hold it; we’ll check. There’s one that should drift under us in a few seconds—half a minute, maybe. We’ll be nearly down to it by then; let’s see if the robot does the same thing. If it does, we’ll know, and can move out farther from this—would you call it ’spray’?”

“All right. Are you following, up there?”

“More or less,” Joe replied. “Update us when you can; I get the impression you’re busy.”

“Thanks. A minute or so,” replied Carol. “We have a check to make on what your height sensor responds to—yes. There. We are stopping again, Molly. Shall we get away from here right away, or—we’d better move; staying won’t tell us anything more.” She reached again for the keys but was too late.

Ammonia is less polar than water. It therefore has a lower surface tension and tends to wet a given surface less readily. The latter quality should have helped when a smallish, half-meter mass of the liquid touched Carol’s shoulder, but the former was enough. The drop did not hold its shape but spread out, covering her helmet almost at once. She was not using her sight on the keys, naturally, but having that sense blocked was quite enough to distract her. She failed to key the new command.

She knew what had happened, of course.

“Molly! Get this thing off me!”

The Human was equally quick at seeing the trouble, but this was not quite the same as knowing what to do about it. Nothing remotely resembling a large sponge was on hand. Gloves, Human or Shervah, were quite inadequate wiping tools. The laser sampling cutters were as likely to boil the armor as the ammonia. It was several seconds before Molly thought of using the heat output from her armor’s refrigerating system, and many more before she could get herself into a position to apply this usefully. By this time, Charley was asking frantically what the trouble was.

Molly was too busy at what amounted to a free-fall dance to be able to tell him, but Carol, who could do nothing but hang onto the robot and keep as motionless as possible, made it clear. Before she was finished, Joe made one of his rare interruptions.

“Carol or Molly! Close the access door to the robot’s keyboard, if you haven’t already!”

“Gravdh! M’Kevvitch!” No one asked for translation as Carol’s glove slapped at the small panel. “Got it. But won’t ammonia leak in through those pressure-sensing openings all over it?”

“I didn’t overlook quite everything. They seal against liquids. I’ve heard of rain. If you have the port shut, it will be liquid-tight.”

“But we’re still in the spray area. More drops could hit us any moment. With the port shut, I can’t move us out.”

“When Molly gets you dry, you’ll have to look around and try to spot a moment when nothing is going to get to you, and do a quick job of…”

“Another drop!” cut in Molly. “I’m falling behind. Who’d have thought we’d need bath towels in this operation?”

“Can you wave your arms, or something, to make air current that will move them away?” asked Charley.

“I’m trying. It works for the little ones, but I can’t see in all directions at once, and Carol’s helmet isn’t clear yet so she can’t either.”

“But why can’t she see through ammonia?” Charley asked almost plaintively. “It’s transparent!”

“It’s ripply!” snapped the Shervah.

Charley once again was visualizing the Human’s battle with Enigma and wondering how many more tests there would be. Why had Molly put herself in the position where she, rather than one of the others, was having to take the physical action against the weird little world’s environment, instead of staying in the boat or the tent and letting the others act as well as think? Maybe the presumptive Faculty policy against letting students get into really dangerous situations was operating, but that couldn’t be the whole story. Carol was down there, too, facing the same risks, apparently.

And why had Molly come up with the idea of using her armor’s heat pump to get rid of the ammonia, instead of letting Carol pass the test herself? The Kantrick, positive from the beginning that they were repeating a laboratory exercise that had been done thousands of times before, almost as certain that the Human was the Faculty member responsible for rating them, was beginning to have doubts about her as a teacher.

Molly, at the moment, was not even a student. She was concerned with keeping the two of them alive, which seemed to mean finding the ideal time sharing between fending off more drops of ammonia and keeping the radiation from her armor’s heat pump directed at Carol’s helmet. Once the Shervah could see out, her side-placed, independently movable eyes could do a far better job than Molly’s stereoscopic equipment at watching all directions for more of the amoebalike blobs.

Carol was waiting, and worrying. The robot was sealed against the ammonia, but had she done the job in time? She had been thrashing around thoughtlessly for a moment or two, and might have flung smaller drops of the stuff in any direction. The machine was safe enough in one sense—it had breakers that would shut down any part affected by short or sneak circuits. A fusion unit melt or blow was a possibility that not even laboratory experience brought to anyone’s mind; the devices were as ubiquitous to all their cultures, both in School and on their home planets, as ballpoint pens had been to the Human’s ancestors. They simply didn’t think of them as dangerous under ordinary conditions—Molly’s fear about the robot’s driving into the cave wall, earlier in her adventure, had been a special case, like a child falling while carrying a pen.

Having power shut down at a time like this was not a pleasant prospect. Was liquid already spreading around inside? Would the device respond to its keys when she did manage to find a safe time to open the access port? Right now it was alternately stopping and resuming descent as drops moved into the path of its height sensor and out again. Each change in motion was a relief to the little Shervah. Neither motion meant safety from more collisions; stopped, they could be caught by the falling drops, and descending they were overtaking them; but changing motion meant the robot was functional. If only she could see!

Feeling turned out to be enough. Another descent started, and this time the metal cylinder failed to stay upright. Feeble as the gravity was, Carol could tell which way she was hanging in her safety ropes. So could Molly.

“Robot power is off,” reported the Human as calmly as she could. “We’re falling. Our terminal velocity seems to be faster than the smaller drops, but not as much faster as we were going down before. Maybe I can keep us clear of them long enough to get Carrie’s helmet dry now.”

“Is that worth doing?” asked Jenny. “Sorry, I didn’t mean to sound quite that pessimistic. Any idea what you’re falling into? That must be a really gigantic cavern; you’ve been going down for minutes.”

“That doesn’t mean too much here,” the Human replied. “If we can get the inside of this machine dry and find our way to where you and Charley are mapping, this will have been just another interesting datum. Trouble is, if we land in a lake or river, we may have to swim this thing to shore. I wonder whether the robot-Carol-Molly system averages out less dense than liquid ammonia. I certainly hope so. The last two parts certainly are, but I don’t know about this piece of metal.”

Jenny was probably the most aware of the grotesque aspect of the situation, in spite of the fact that she could see it only by imagination. Her native world’s gravity was nearly twice that of Earth, and the mental picture of her two friends carrying on a more or less reasonable conversation while falling through darkness toward some point they could not sec and whose distance below they couldn’t guess seemed dreamlike in some ways and irresponsible in others. Like most intelligent beings, she had a sense of humor. She had time to reflect how lucky it was that her normal expression of it was not audible and would not be carried by the translators; lucky, since the present situation wasn’t really funny and a laugh like Molly’s or a buzz like Joe’s would be most inappropriate. Her friends might be dead in the next few seconds.

She controlled the body-ripple that would have corresponded to a giggle had another Rimmore seen it, and listened tensely. Falling took so long here!

“Good going, Molly! I can see!” came Carol’s voice after what seemed minutes of silence.

“What’s around you?” asked Charley.

“Large drops of juice, against a dark background. What else? We’re still falling. Mol, we’re going to hit that one; can we—good! I don’t know if you moved it or moved us. Too bad we don’t have a Parkemm here; your arms don’t really make good wings, and mine are worse.”

“The last time you wanted to fly was on Sink, when you were beginning to wonder whether our suits were going to keep us warm after all.”

“Well, we practically did. The gravity was only a tenth of what it is here, and we could keep ourselves in the air—well, off the surface—nearly all the time by jumping. The main point was to keep out of contact with the ground.”

“But even in that gravity a Parkemm couldn’t have flown. A trace of helium won’t…”

“Watch it—there’s another drop! Anyway you’re quibbling.”

“I can’t keep this up. I’m afraid we’re going to have to put up with being wet—Lord, we certainly are! Look down there, if that’s really down!”

“It’s the way we seem to be going. It…”

“What is it?”

“Just listen, Charley. We’ll report when we have time, and until then infer what you can from what we say to each other. I’d say it was too bumpy to be a lake, but with these big drops merging into it and taking awhile to settle, maybe it’s just because I expect a wave on a lake to go away at a decent speed.”

“It’s too big to be called a puddle. I hope it doesn’t rate as an ocean,” replied Molly. “Here we go. Any bets on whether we float?”

“Not with my credit. I don’t think there’d be room for an ocean in a cave, even with this gravity. Will you hold my hand? My brain trusts these ropes, but the rest of me doesn’t, quite.”

“Right. And hold the robot, too. You need it more than you need me.”

“That’s another point where my brain and the rest of me don’t agree. We’re not floating, are we?”

“We’re not at any surface yet. I’d like to have seen our splash from outside; just a slow-motion replay of an ordinary one wouldn’t cover the surface tension effects. There, that seems to be surface, a few meters that way.” Molly pointed with her light.

“We can see all right now, Charley,” Carol remarked rather savagely.

“How far?”

“Hard to tell.” Molly took over. “Tens of meters, I’d say. There’s nothing by which to judge the distance; we’re just hanging here. Come on, Carol, let’s see if we can swim effectively enough to drag this thing to the surface, if that is the surface.”

“It must be. The bubbles that came under with us seem to be heading that way, though they aren’t in much of a hurry. If it is, we’re traveling; the bumps we saw from above are gone—we must be away from where the spray is falling.” The women fell silent and concentrated on swimming, which is not easy in armor. Molly was good at it under more normal circumstances, and the Shervah caught on quickly watching her. The metal cylinder was certainly denser than the liquid, but Molly found herself able to drag it upward by herself even before her friend was able to offer effective help. Newton’s third law, the inertial aspect of swimming, enjoyed considerable advantage in Enigma’s gravity even if Archimedes’ Principle didn’t. Even so, it took some minutes for their helmets to break the surface.

“Nothing to report,” Molly said after sweeping her light around. “I assume there’s a current because we seem to be away from the fall already, but if this is a river we can’t see any bank, we can’t see any sides or top to the cave, and we don’t know which way or how fast we’re going. So much for finding your mapped areas.”

“Then Jenny and I map southward and try to find your ammoniafall,” replied Charley promptly.

“Which we probably won’t stay anywhere near.”

“Can you suggest anything better, Carrie?”

“No. Sorry, Charley. And maybe this will still be a river you can follow.” Molly looked at her companion in some surprise, but her helmet was pulled below the surface by the robot at that moment and she missed whatever expression was on the Shervah’s face. It took her half a minute to get up again, and some seconds more for the liquid to drain sufficiently from her faceplate to permit clear vision.

She decided that tact was more important than satisfaction of curiosity. So was survival.

“Carrie, we don’t float. We can’t stay up forever on muscle power. I hate to suggest it, but I think we drift to wherever we’re going along the bottom of this brook.”

“Why go anywhere?” asked Charley. “The robot isn’t dragging you; why not wait for us to find you? It will no doubt take quite a while, but your armor will keep you alive.”

“Of course. I’d gotten so committed to the value of keeping going that I’d forgotten we didn’t have to!” exclaimed Molly. “We’ll just wait! When you find the river, Charley, you can follow it down to the fall and over, and we can’t possibly be very far from its foot. If we let ourselves sink to the bottom, we can probably stay put; and when you and Jenny get down here, you’ll be able to see our lights even if we are underwater—I mean…”

“Sorry.” The Shervah’s voice was softer and more apologetic than any of them had ever heard it. “We can’t wait here.”