The Green World

by Hal Clement

  "Variable. Shallowest in the wider joints; in the very narrow ones, up out of sight."

  "Suggesting that they've been washing out for some time since the original settling. Anything organic in them?"

  "Nothing turned up yet."

  "Do they extend below the present river level, or what?

  "They're at least down to it. We couldn't do any major excavating."

  "If they run much below," muttered Lampert, "I'll join the roster of geophysicists who have been driven off the rails by this woozy world. Well, let's assume as a working hypothesis that the volcanic activity is relatively recent. That will at least have the advantage of keeping me sane, until something comes up to disprove it." He finished his meal in silence, while McLaughlin gave a reproving lecture on the matter of wading.

  There was still a little daylight to go when all the men had eaten; and Lampert, Sulewayo and the archaeologist took the helicopter up the main canyon to check on the possibility of walking to any really new deposits.

  They were sure, from changes of color already seen at various levels up the cliff face, that these existed. But it appeared that the lowest of them did not reach river level for more than a dozen miles. The distance was less mapwise, but the canyon, winding back and forth around what the geophysicist still felt must be joint-bounded blocks, went a good two miles in other directions for each one that it led eastward. Realizing this, the explorers lifted the helicopter and began checking as close to the cliffs as Lampert dared at higher levels. In this way they worked back toward the camp site. Once again it was Mitsuitei who first spotted something of major interest.

  "Found another city, Take?" asked Sulewayo at the other's call.

  "Not exactly. It's — well, I guess it's really a system of those joints you keep talking about. Still, it looks awfully regular." He sounded a little wistful.

  "It does." The paleontologist nodded slowly. "As you say, it's probably a joint system. Also, it's probably full of volcanic ash, if my eyes don't deceive me. Rob, what's the chance of a landing on one of the shelves? There are at least three formations accessible on foot from that point; and I could get some more turf samples to make or break your peace of mind, while I was doing my own work."

  Lampert examined the area carefully. Like Earth's Grand Canyon, this one receded from time to time in shelves where softer layers of rock had worn further back, or the orogenic processes had paused to give the river a longer bite at that level. The cracks Mitsuitei had seen formed a neat crisscross pattern on the top of one of the shelves. Some of them betrayed their nature by emerging from its vertical face. It was admittedly an unusually small-scale joint pattern, at least for this mountain system, and might well contain readable evidence of the forces which had shaped the area.

  However, they had only one helicopter. Lampert slowly shook his head in negation.

  "I'm afraid not, Ndomi. Your shelves may be big enough, but they're not level enough. I'd have to make a swinging landing, and I'm not that good a pilot."

  "Well, how about letting me down on the ladder? We have a hundred feet of that, so you could be up above the next shelf while I went down. You'd have plenty of blade clearance. That next level goes back a couple of hundred feet."

  "That might be all right." Lampert spoke hesitantly. "You certainly have the right to risk your own neck on the climb if you want to. We won't try it tonight, though. I'd like to check with String on the advisability of your being there alone. The place looks pretty hard to reach for anything that doesn't fly, and I don't know of any really dangerous flying things on this world; but we'd still better check."

  "All right with me. I'd just as soon have a full day, anyway."

  "If Ndomi will be spending a day alone up here, how about having String take me to the other place, and settle that point once and for all?" asked Mitsuitei as the helicopter eased downward toward the camp. "That would still leave Hans and you to form another team for whatever else you want to do."

  "That should be all right. It'll depend, though, on whether String thinks it's safe for a man to work alone on that shelf."

  The proposition was put to McLaughlin as soon as the machine was landed. To Lampert's surprise, the guide gave a qualified approval "Remember," he concluded, "I don't know what lives on the cliffs. It's country I've never covered. All I'm saying is that no Viridian animal I know of could get there, except flying ones; and they're nothing to worry about, especially in the daytime. I'd like to go with you to look over the place when you take him up tomorrow, and strongly recommend that he carry a communicator as well as a weapon; but unless I see something you haven't mentioned when I do go, I would say it was all right..."

  Once more the Felodon reached the river, but this time it did not cross. It was no longer heading straight for the helicopter. Hills had not altered its course, but the cliffs had. They formed a wall on its right which was too nearly vertical for its agility and strength. Even this barrier, however, had caused no visible hesitation or doubt. It had swerved, followed the base of the wall to the point where the river emerged and plunged in as promptly as it had done before. Few amphibians have ever lost the art of swimming when their larval gills vanished; the feeble current meant nothing to the Felodon.

  It turned upstream and went on its way.

  IV

  Ndomi Sulewayo had pursued his occupation on terraces of Earth's Grand Canyon, on cliffsides of Fomalhaut Four's highest range and in badlands on the dimly lighted Antares Twelve. The physical hazards of his present position troubled him little. McLaughlin had agreed that the ledge where the paleontologist had been left was inaccessible to the larger carnivores, and had merely issued a final warning about poisonous "lizards." The primary danger, as nearly as Sulewayo could see, was that something might happen to the helicopter. He certainly could not rejoin the others on foot. He was facing a sheer wall some sixty feet high. A score of yards behind him the terrace ended in another straight drop of several hundred feet. A quarter of a mile on either side, the flat surface ended; to the west, by narrowing until the two walls became one; at the other end, it was cut off as far as he was concerned by a joint penetrating apparently the full depth of the canyon.

  There were several other cracks in the wall facing him. Like those in the tributary canyon explored by Krendall and Mitsuitei, these were packed with volcanic detritus. This was hard to reconcile with the suggestion that erosion had been long at work. In such a case, the higher portions should have washed away long before the material found at the canyon bottom.

  Examination at close range suggested a possible explanation. The tuff at this point was fairly well cemented. It seemed reasonable to suppose that the joints had been present before the mountains had started to rise; that a volcanic mud flow had filled them with detritus; that the new material had then been cemented by dissolved material coming from above. This would make the top levels of the tuff more resistant than those lower down, where the cementing minerals had not reached, and account for what had been seen so far.

  The hypothesis also implied a plentiful supply of fossils. Volcanic mud flowing into a crack in the ground should carry plenty with it. Sulewayo set to work with a hammer, and was presently soaking with perspiration.

  He was tempted to remove some of his clothing; but this had been treated chemically to repel Viridian insects and caution prevailed. McLaughlin had not mentioned any dangerous biters or stingers, and in all probability his blood would not be to the taste of any such creatures on this world — but if the mosquito or tick did not learn that fact until after it had tried, Sulewayo would hardly profit by it. In any case the temptation to strip passed quickly. In only a few minutes, his attention was fully occupied by his work; for the expected fossils proved to be present in very satisfactory numbers.

  Most seemed rather fragmentary. Apparently the original creatures had been tumbled about rather badly before the medium hardened. However, the remains were definitely bones, as he had expected and hoped. For some time Sulewayo wa
s occupied alternately digging out more fragments and trying to fit the more hopeful-looking specimens together, although he had no success at the latter job. Then evidence of a more complete set of remains appeared, and he instantly slowed down to the incredibly meticulous procedure which marks a paleontologist anywhere in the universe.

  At this time he had cut perhaps a foot into the tuff for the full three-foot width of the crack and from terrace level up to about his own height. In spite of its apparently firm texture, the rock was extremely soft; and the old question about erosion was reappearing. Big pockets of extremely crumbly material had been responsible for most of his speed. Now, however, with the usual perversity of the inanimate, a firmer substance was encountered, apparently encasing the bones he suspected of existing a little farther on. This combined with his increased care to bring almost to a halt the removal of rock from the cleft.

  The bones were there. Perhaps they had been betrayed by a discoloration of the rock too faint for him to have noticed consciously; perhaps something more subtle is involved in the makeup of a successful field worker in paleontology, but as flake after flake of the matrix fell away under his attack a shape gradually took form.

  At first a single bone which might have been an unusually short digit or an unusually long carpal —or, of course, something totally unrelated to either—was outlined. Then another, close enough to suggest that their lifetime relationship might have been maintained. And another — Sulewayo failed to hear the approach of the helicopter until its rotor wash from a hundred feet above lifted the dust about his ankles.

  Knowing that Lampert would be having trouble holding that close to the cliff side, the paleontologist reluctantly hooked his equipment to his belt and started up the ladder. Five minutes later they were back in the camp, with Krendall listening eagerly to Sulewayo's description of his find.

  "It's certainly a vertebrate, Hans. That stuff can't possibly be shell or wood. It's almost certainly a land dweller —"

  "Likely enough in that sort of rock, anyway."

  "— because I got enough uncovered to be nearly certain that it's a foot. Certainly a limb that would not be needed by a swimmer."

  "Like an ichthyosaur?" queried Lampert innocently. Sulewayo grinned.

  "Quite possibly. More likely one of our ubiquitous amphibids, though. Certainly something worth getting out, since the general idea is to get an evolutionary sequence of some sort."

  "I suppose that means you'll want me to date the eruption which filled all these cracks with detritus, then."

  "Sure. But there's no hurry. Tomorrow will do." Lampert found he had no answer to this, and Mitsuitei managed to edge into the discussion. He had spent the day with McLaughlin, as he had hoped; and mere failure to find paving stones had not damped his ardor.

  "I suppose you and Hans will both want to go up the cliff tomorrow," he remarked. "In that case, Rob might as well stay with String and me. It will speed up the digging back at my hill."

  "Are you still scraping dirt off that thing?" asked Sulewayo in mock surprise. "Didn't one day indicate that it was a joint pattern like the rest?"

  "Not yet. We haven't gotten down to rock over any place where your cracks should be. The root tangle of the taller trees slows the digging. I admit the rock is limestone like the cliff, but there's still no evidence why those trees grow so regularly."

  "That's just what we've been saying all along; but you keep looking for the remains of a city."

  "I gathered, Ndomi, from your recent conversation that you were digging for a land animal on the basis of three bones. Either you are working on hunch, which destroys your right to criticize, or you are reasoning from knowledge not available to the rest of us. In the latter case, you should be at least open-minded enough to credit me with equivalent knowledge in my own field."

  It was Sulewayo's turn to have nothing to say; he had honestly supposed that the archaeologist had been taking the "city" hypothesis no more seriously than the rest. He apologized at once, and peace was restored. Lampert sealed it by agreeing to Mitsuitei's suggestion.

  The rest of the evening was spent in detail planning by the two groups. At sunset, all turned in to sleep behind the protection of the electrified fence. Even the guide regarded this as an adequate safeguard.

  Apparently his opinion was shared by at least one other. The Felodon had spent most of the day under water, part of the time in the canyon fairly close to Lampert and Krendall and later down the stream by the site where the guide and archaeologist had been working. At neither place had it emerged, or shown the slightest sign of wanting to attack. McLaughlin's reference to the strange instinct of the creatures seemed justified. It certainly could not see the men, but just as certainly was aware of their presence.

  What it was about the alien visitors which exercised such an influence on the minute brain of the carnivore, no one could have said — then. Any watcher who had supposed, from its earlier actions, that it was moved by a desire for new and different taste sensations would have had to discard the notion now.

  With the men safely settled down behind their fence, the beast suddenly turned back downstream. It had returned to the camp site at the end of the working day. In an hour it was in the jungle below the canyon; in another it had killed, and was feeding as it had the moment before the hum of the helicopter had first attracted its attention. This time it finished the meal in peace; and once finished, did not show immediate signs of its former obsession.

  Instead it sought a lair and relaxed, blending so perfectly into the undergrowth and remaining so silent that within a few minutes small animals were passing only feet away from the concealed killer.

  Robin Lampert was only a fair statistician, but if he had been acquainted with the moves of that Felodon during the last few days, even he would have been willing to take oath that more than chance was involved. He would probably have wanted to dissect the animal in search of whatever mechanism was controlling it.

  But Robin Lampert knew nothing of the creature. Neither did Takehiko Mitsuitei; and that was rather unfortunate, for the lair it had selected was on the same hill as the archaeologist's digging site, and a scant quarter mile away from the pit Mitsuitei had left.

  The rising of the green sun was not visible the next morning. The ever-present mist had thickened into a solid layer of cloud, and hissing rain cut the visibility to a few hundred yards. The helicopter felt its way down to the hill with radar, landed on the river, taxied on its floats to the bank and was moored. Lampert, McLaughlin and Mitsuitei emerged, the scientists laden with apparatus, and started up the hill toward the site. The guide carried only his weapons.

  The equipment was not of the sort Mitsuitei was accustomed to using. It actually belonged to Lampert. Normally it would not be used in an archaeological dig, any more than it would have been had they been fossil hunting; for neither activity takes kindly to any sort of automatic digging machinery. Lampert had suggested its use, however, in order to get a rapid idea of the nature of the soil cover, bed rock and joint structure of the hill. If evidence warranted, it would be abandoned for the slower methods of digging. If not, a few hours would permit them to learn as much about the area as many days of work with slower equipment.

  The hole Mitsuitei had already dug was part way up the hill, in a space cleared of underbrush by a flamethrower. Several other such clearings were in the neighborhood. As the archaeologist had said, he had made more than one attempt at digging which had been frustrated by roots.

  Somewhat to Lampert's surprise, it was possible to tell even from ground level the orientation of the taller trees which had been so prominent from the air. Even the smaller plants showed signs of some underground influence. Between the tallest trees, tracing out the straight lines the men had seen from above, the underbrush formed an almost impenetrable wall. Elsewhere foot travel was easy, though the surface was by no means barren. Lampert understood how there might indeed have been difficulty in digging on one of the fertile lines, and admitt
ed as much.

  "That's the trouble," responded Mitsuitei. "I'd like to get down right at such a point, to see what's underneath. It seems to me that paving might be responsible, if they'd used the right materials. Lots of civilizations have used organic substances which decay to good fertilizer. Then there might be the remains of a sewage system, which would account for richer soil —"

  "After the time which must have passed since me place was buried?"

  "It has happened. In such a case, of course, trace elements rather than nitrates or phosphates are responsible. That's what I suspect here."

  "But wouldn't it be better to dig where you actually have — in the middle of a block, if that's what it is? Then you'd be fairly certain to hit a building, which should be richer ground than a street."

  "Only if you actually strike artifacts. The building itself might be much less well preserved than a paved street. However, you are the one who's handling that mechanical mole. Dig where you want, and see what you can learn about this hilltop. Just get me at least a couple of cores from my 'streets' before you're done, please."

  Lampert nodded and proceeded to assemble his equipment. The "mole" was a cylinder about five centimeters in diameter and three times as long. A cutter-lined mouth occupied one end, while the other was attached to a snaky appendage which was wound on a fair sized drum. A set of controls knobs and indicators were mounted near the center of the drum.

  The geophysicist set the cylinder on the ground mouth downward, pushing it into the soft earth far enough to assure its remaining upright. Then he turned to his controls and after a moment, with very little noise, the cylinder began to sink into the ground. In a few seconds it was out of sight, trailing its snaky neck after it.

  The men watched it in silence.