“I take it your immediate danger is over, Molly and Carol.”
“Yes. Now I can start thinking about a bath and a good meal again.”
“Or maybe about the job,” added Carol.
“Even the job. I think we may as well take that can out and remove one more immediate worry. Also, I’d like to know if it’s liquid or not.”
“Good,” said Joe. “Then as soon as you reach the boat, Jenny, please set Exit Lock Five—the little waste-disposal one near the shop—for automatic cycling, and the shop master inside for Activation Code Two. I may as well put the new machines to work. There should be about three hundred of them ready…” “What?” gasped Molly.
“—and about two hundred more to be finished. That will be enough, I hope. I made the bodies out of silicon and carbon compounds instead of metal, so the only raw material shortage is in electrical contacts; we’re low on silver now. The shop equipment can handle them up to a few more than five hundred.”
“But what are they?”
“You will have guessed, Molly. Small mappers, each with its own model storage unit, all interconnected electromagnetically, all radar equipped. They will be spread out through these caverns, plotting as they go, assembling a model of the interior of Enigma. Charley’s estimate of the length of time it would take to do it by ourselves was very discouraging, and it seemed best to use equipment that wasn’t limited by having to carry living operators. As soon as Jenny gets to the boat, she’ll start sending them after me, and I can begin mapping from these incurrent caves inward. They should get to your end of the planet—I’ve programmed them to stay in touch, so they won’t diffuse and try to map the whole sphere, and to go as far down as possible to make the trip a minimum-distance one—in a couple of weeks.”
“But…” Molly started to vent her feelings, and fell silent. Carol was less restrained.
“You said this end was more likely to have the life forms that restored the gas. Why not send them here first?”
“Jenny has specimens of those and will be able to tell us fairly soon whether that hypothesis is right. Charley and you two are already mapping the summer end. If you hadn’t managed to charge your batteries, naturally I’d have sent the new ones looking for you first. That was Activation Code One. Luckily, I was able to tell Jenny to key in Two; but I waited until I heard from you two, of course.”
Chapter Twenty
Of Course I Couldn’t Know
Once again, Molly was unable to find the right words. The vision of hot food and hot bath went glimmering as it had before.
Carol happily decided, aloud, that the next thing to do was resume their trip down the river toward Enigma’s heart. It was only a matter of time before Charley made contact with them, and if for some reason the Kantrick failed, the new mappers would do the job. Five hundred certainly ought to be enough. With their armor batteries charged and the robot and its fuser standing by, there was nothing to keep them from work. Her beautiful brown fur might be sticky, matted, or even starting to fall out, but her armor would take care of any that did. She could shampoo later.
There were lots of questions to be answered. Was Enigma as spongy and cavernous as their experience was beginning to suggest, or was this something local? Were the caves really kames, and if so, were the original ice bodies that had molded them comet nuclei or something else? If they were comets, how had they incorporated themselves into Enigma’s mass without blowing up in the process, since the kinetic energy of a typical interplanetary collision is more than enough to vaporize iron? If they were comets, were there still some of them at greater depths to be found in their original state, to justify Molly’s ice hypothesis? If the basic idea was right, how had the silicates consolidated into rock hard enough to support these deep caves? Was Enigma really as young as its sun had to be? If so, how had it managed to develop highly complex life forms? Was biochemistry really the answer to the air-circulation problem? Was it also the answer to the problem of why the little world had air at all—their originally assigned research question? It could be; if gas precipitated as solid before getting far from the surface, it could hardly escape.
Even Molly, thinking all this over, was able to forget her personal discomfort and join in the planning. Clearly, they had to go deeper. However good Joe’s new little robots might be, they would not be able to select biological specimens for detailed analysis; researchers would have to do that themselves. Furthermore, geochemical data were badly needed, too; the lasers and picks would have to be put to more use.
Perhaps it was no longer really essential to follow the river, as there was now another way for the others to find them and get the group back together; but since they were now frankly seeking for a route down, the river seemed the obvious guide. Also, it would clearly be much easier for even the new robots to find rivers than explorers.
With the anxiety about the robot allayed and the collecting can of ammonia water poured gratefully out on the rock where the machine had stood so long, Molly and Carol resumed their journey.
Charley, too, was following a river—Jenny’s—but there was so far no evidence that it was either the same one as Molly and Carol’s or one of its tributaries. He, too, was finding much life. His verbal descriptions irritated Carol; the organisms were either decidedly different in structure from those she and Molly had been seeing, or he was doing a very poor job of describing. He was collecting specimens, of course, so there was no point in being critical until these could be examined, and the Shervah managed to restrain herself.
Time went on, on the whole happily. Everyone but Jenny got deeper into the planet, though for Joe it was by proxy; he remained at the antarctic surface, finding and charting more and more wind-caves and sending a small swarm of mapping robots into each as he found it. The halo of fist-sized cylinders that accompanied his own craft was growing smaller, though replacements were still homing in on him from the boat’s shop.
Even Carol and Molly were finding a gradual change in the life forms around them, though not enough, the former insisted, to account for the discrepancies in Charley’s descriptions. The temperature was rising significantly, though their armor prevented them from noticing the fact through their own senses. The real warning was the appearance on the rock around them of a faint, white mold.
Even Carol had reached the point where not every life form had to be examined closely, and neither had a container left in which to collect anything new, but this stuff got thicker as they progressed, and finally both felt that it deserved detailed attention. Molly scraped some from a convenient surface and spread it on her palm where they could both look at it. They saw a mass of needlelike crystals matted in a way that reminded the Human of the sparkling stuff she had seen in the first cavern.
This, however, was glassy rather than metallic. There was something else familiar about it, and as the women watched, the mass abruptly lost most of its whiteness and then slumped into a tiny puddle of liquid on the palm of Molly’s glove. She didn’t feel the local heat loss, as her suit had very efficient distributing apparatus even at the thin gloves, but what had happened was suddenly plain enough.
“Frost! Water!” the Human exclaimed. “What became of the ammonia? What’s the river made of now?”