“Personally,” remarked the Rimmore without waiting for Molly’s answer, “I’m happier not having my imagination limited by what someone has decided is the right answer. I know some discipline is needed for that particular tool, that’s why we were educated in the first place; but if I’m going to be confronted, back on Classroom, with a ’gramful of other people’s notions of why this place still has atmosphere, I want the one I come up with—or we come up with—to show up decently in the list.”
“Do you feel that way, too, Molly?” repeated the Kantrick.
“Yes, I think I do. Personally, I can believe that no one has been down in this cave before; I discovered it in such a silly fashion, and surely no one could have expected it.”
“Wind from the hole. For that matter, the wind from Carol’s trap, come to think of it.”
“Well, maybe, Joe. Anyway, I agree with Jenny about doing our own thinking, and it’s probably a good idea for a few more years for us to do it with lots of independent checkers. Anyway, I’m not worried about the philosophy just now. Work—data collecting and thinking—first; worry about getting hick to the rest of you alive, second—and maybe that will climb to first later; worry about what the Faculty thinks of my work, and what my friends think of it, not to mention what I think of it myself, third. First point, Joe—the wind is getting stronger, I think.”
“You can feel it?”
“I’m pretty sure. Just a minute while I get a handful of this stuff.” Molly reached down and collected some of the powdery crystals, tossing them upward. “Yes, they’re drifting backward quite a bit faster than before.”
“Is it strong enough to do anything to the undisturbed crystals?” asked Jenny.
“Just a minute. Not generally—but yes, around the base of the robot itself, where there are eddies, some of the stuff is being blown away. I’m starting to leave a blowing dust trail—a pretty, sparking one—behind me.”
“Suggestion. You could be approaching a wall of the cave, with the wind coming from a narrow, or relatively narrow, passage,” the chemist returned.
“Good thought. I’ll go back to narrow beam and look ahead as far as I can.” The others waited silently. Carol, now outside with the rope-laden robot, continued her work on its controls, but even her attention was divided. “Nothing in sight yet.” Three more times, at roughly one-minute intervals, Molly repeated this message. The situation was not really boring, of course; merely tense. A well-remembered chemistry exercise in the isolation lab on Beryl had been similar. There had been automatic dampers, of course, that might work in time to forestall an explosion; but the lab itself was on tall stilts, which combined with the little world’s lack of atmosphere to prevent the transmission of shock to surrounding structures if they didn’t. Molly had wondered at the time why she had not been allowed to perform the experiment by remote control; Rovor had been quite indignant about it. Now she thought she knew the reason. Here there was no equivalent to the dampers, but she found herself quite free of panic. The tendency for familiarity to breed calmness, if not actual contempt, was almost universal, not a Human peculiarity.
Carol by this time had satisfied herself about the key responses and was riding up the hill at some five times the pace her vehicle’s predecessor, or predecessors, had taken. She could have set in a still higher speed, but prudently used one within her own running capabilities. She was not planning to get off, but she had not planned to fall into a crater before, and Molly had not planned to go underground.
And Joe had certainly not planned to blow away, she was sure.
She watched everything around her carefully as she went; if the rope failed for any reason, her memory would serve one of its functions. The cord, which Molly would have thought of more as fishline than rope, had been fastened to a rod driven into the ground near the base of the hill, and way paying out comfortably from the top of the cylinder; Carol kept carefully clear of it. It was thin material, but far too strong for her to break if she became tangled in it. She had a knife, of course, but felt strongly that having to use it would be glaring evidence of carelessness.
“Still nothing in sight” came Molly’s voice.
Over the edge of the crater. It occurred to Carol that the air from below must be cooler than surface atmosphere; it would not have poured down the side of the cone to guide the robots otherwise. Down the slope, over the central hole. A straight letdown into the hole; she had not altered Joe’s original programming on this point. Almost at once a steep slope that the machine treated as a surface, flying into the wind—down the slope—at its set speed. Carol herself could feel the wind at first; then it decreased rapidly. She could still see fairly well without her hand light and was not surprised that the passage was growing larger.
“Still nothing in sight.”
Now it was a good deal steeper, and the little Shervah could picture her giant friend helplessly rolling down into the darkness ahead. Within seconds she had to use her own lamp, and before long the surface leveled and was covered with the same sort of sand as that composing the cone above. Carol was not surprised; she had guessed how the cone had been formed.
“Molly, I’m about at the place where you must have let the robot catch up with you. It’s past a steep slope of rock where you certainly couldn’t have stopped yourself, and I can see marks in the sand that you probably left.”
“Good. It’s awhile yet to the cave. Joe, I suppose you’re tracking Carol’s machine as carefully as possible.”
“I am indeed. I already suspect the cause of the earlier reading uncertainties. I should have thought of it earlier.”
“I’d welcome you to the club, if you weren’t the founder. What’s the answer?”
“Refraction index. The electromagnetic waves—radio waves—are not only absorbed by the rock but slowed by it, so both timing and direction measurements are affected. The rock of course is not uniform, and every time either the transmitter or the receiver moved, the beam was going through a different length of different medium. Hence kilometers of probable error.”
“Have any of you studied enough about Humanity to have gotten the term ’twenty-twenty hindsight’ into your translators?” asked Molly.
“I have,” said Charley. “Very appropriate.”
The Human did not have time to express her surprise; her attention was taken up by something more immediate.
“Cave wall ahead, I think!” she called suddenly. “The wind is a lot harder. I should have told you earlier the floor is bare rock; it looks as though the crystals couldn’t hold up in the draft.”
“Bare rock, or the sticky stuff?” asked Jenny promptly.
“Rock. I’m sorry; I should have made more checks under the crystals. We can do it on the way back, or if Carol has time she can pause coming over—but watch out, Carol; remember the crystals are a good deal deeper than your height, at least in some places, and the stuff at the bottom is quite adhesive. You’re not as strong as I am, and if you couldn’t pull loose the situation would become rather awkward.”
“I’ll control myself,” the Shervah assured her listeners. “Are you close enough to the cave wall to see where the wind is coming from?”
“Quite close—two or three hundred meters, I’d guess—but I can’t see any passages or openings in it yet. I should go right to whatever it is, so I’m looking straight ahead, but still just dark rock. That may be the trouble, of course; the passage won’t be much, if any, darker. I’m very close now—fifty meters—less; still nothing—uh-oh. Joe!” “Yes, Molly?”