"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 admitted 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 the 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 control 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. Perhaps thirty seconds after it disappeared, there was a minor convulsion in the neck, a momentarily rising hum from the machinery, and a plug of dirt about two centimeters in diameter and five long was ejected from a port in the center of the drum. This was seized by Lampert and examined briefly, then tossed aside. "The soil is pretty deep," he remarked.
"How far down did that come from?" asked Mitsuitei.
"One meter. That's the sampling interval I've set in it, for now. If it meets anything much harder or easier to penetrate, it will warn me and I'll grab them more frequently." Conversation lapsed while two more samples arrived and were inspected. Then a light flickered on the panel, and Lampert reset one of his knobs; and almost immediately a core of light gray limestone was produced.
"Apparently the same stuff as the cliffs," said Lampert after examining the specimen. "Do you want to go any deeper, or drill a few more holes to get an idea of the contour?"
"How fast will that thing go through limestone?"
"A couple of centimeters per minute. It's too small to pack a real power unit."
"Give it five minutes, just to make sure it isn't a building block."
"Ten centimeters wouldn't give you a whole building block."
"A sample from that far inside one would tell me what I want to know. You rock-chippers don't seem to think that archaeology is a science yet. Let me have that first core, too." Mitsuitei looked confident to the point of being cocky, and Lampert let the mole burrow on. The second core came in due time, and the little man set merrily to work with tiny chips from the two stone cylinders, a pinch of the lowest soil sample which had been acquired, a small comparison microscope and a kit full of tiny reagent bottles. Lampert used the time the tests consumed in reversing the mole and resetting the equipment on a new spot. By the time the little mechanism had gnawed its way once more to rock, Mitsuitei was forced to admit that the formation appeared to be natural.
He did not seem as disheartened by the discovery as might have been expected. He simply waited for more cores, his narrow face reflecting nothing but the utter absorption Lampert knew he experienced whenever a problem arose in his line. In spite of his apparent tendency to jump to conclusions, Takehiko Mitsuitei was an experienced and respected member of his profession. Lampert knew enough about his record to be perfectly willing to accept his instructions for the present.
A series of holes was drilled, from the original position toward one of the "streets" forty yards away from it. After each the archaeologist admitted with perfect cheerfulness that there was nothing inconsistent with the idea that the hill was a perfectly natural formation. He still insisted, however, that the regular lines of trees, reinforced as they were by the undergrowth pattern, required explanation.
Lampert admitted this, but felt that he knew what the explanation would be. After all, volcanic residue is more than likely to contain the trace elements vegetation requires, even on Viridis.
Finally the time came to get verification—or the opposite. The flamethrower had to be used this time, and for several minutes clouds of steam swirled about the men as its blue-white tongue fought the sappy, rain-soaked undergrowth. Then the mole and its controls were wheeled into place, and the little robot once more nosed its way out of sight.
"I don't suppose you want any samples above the regular rock level, do you?" asked Lampert as the machine disappeared.
"I think it would be best if we took them as usual," was the reply. "For one thing, we should try to learn the depth at which the soil composition changes—we are at least agreed that it changes in some manner, after all."
"True enough." The geophysicist set his controls, and the process continued—a process familiar now to McLaughlin as well as the scientists, for the guide had caught numerous glimpses of what was going on while he prowled about the work area on self-imposed guard duty.
Mitsuitei took the crumbly soil cores as they came, examined them quickly—they were arriving every few seconds—and filed them in numbered compartments in a specimen case he had opened. Detailed stratigraphy would come later. For some time there was no gross evidence of change in the soil; not, in fact, until his first case had been filled.
"Can you stop that thing for a moment, Rob?" he asked at this point. "I don't want to lose track of these, and will have to hold up while I open a new case."
"All right. I thought you'd want to stop for thought soon anyway."
"Why?"
"Because the mole is nearly four meters down, well below the depth at which we hit bedrock before, and is still in soil."
"Eh? But—but it's still ordinary soil; none of your volcanic ash."
"Tuff had been eroded out of a lot of the joints in the cliffs. There's no reason to expect it to be at the same level as the surrounding rock."
"That's true." Mitsuitei paused in thought for a moment. "If we keep on going straight down, we may just be working into a natural crack, as you say. Might it not be better to drill several holes within a few square yards here, to determine whether it is a narrow joint such as you expect or an actual edge to the rock at this level?"
"Maybe the edge of a roof, eh?" Lampert chuckled, but spoke in a manner which could give no offense. "I can do better than that. Don't need to pull up and start over; simply drill horizontally from where we are now. Shouldn't take long to get dimensions, if that's all you want." He halted the robot momentarily, and from a compartment in the drum removed something like a small theodolite mounting. This he set up on a short tripod over the point where the neck of the mole emerged from the ground, and set a pointer at right angles to the line of tall trees. Then he started the digging again.
V
Four starts in as many different directions and twenty minutes of time showed fairly conclusively that the line of vegetation which had given rise to the "street" theory was growing along a straight crack, apparently a fairly ordinary joint, in the limestone. While several more holes would have to be drilled to prove it, even Mitsuitei was willing to admit that in all probability the remaining lines would be found to be over similar cracks.
"You must admit, though, that the regularity of this joint pattern is pretty unusual," the archaeologist said at length.
"It's far from being unknown," Lampert replied. "I got my first large taste of it in my student days back on Earth. Fly over the mesa country in southwestern North America sometime. Most of the joints there are invisible from a distance, of course; but at the edge of a butte where weathering is most prominent the blocks have frequently started to separate, and the thing looks as though it had been put together from outsize bricks."
"Hmph. Seem to remember something of the sort myself, now that you mention it. I did some digging in that area, too. I shouldn't have connected that sort of country with what we have here, though."
"Different meat; same skeleton," replied Lampert.
"But how about this volcanic ash, or mud, or whatever it is, which at least fills the joints we saw in the cliff? That's not so usual, is it?"
"Not in my experience. But granting the joints and the volcanoes, there's nothing really surprising about it. Incidentally, we don't know that this crack we're standing on has the same filling. We'd better bore down again to make sure. At least we may get some idea of the date of the volcanic action compared to that of the orogeny that tilted the block where we're camped. If there's tuff down here too, it will substantiate the idea that the vulcanism is the older."
"Why? Couldn't ash have settled down here as well as up there at substantially the same time?"
"It could. But I'd bet a fairly respectable sum that the tuff we saw in the canyon was from a mud flow, not a fall of airborne ash. That could hardly have reached the top of the cliffs—actually, the opposite slope of the mountains, where Sulewayo is working—and this area simultaneously."
"Maybe from different eruptions? I get the impression that this world has a slight tendency to produce volcanic fields rather than individual cones or flows."
"Might be. Chemistry will probably settle that question." During the latter part of this discussion Lampert had directed the mole once more downwards, and every half meter of travel another core was added to the collection. At six and a half meters below the soil the first solid specimen arrived; the others had been held together only by roots. This one, however, caused the two scientists to look at each other. Lampert nodded slowly, with a smile. Mitsuitei gave a shrug, and let an expression of resignation play over his usually impassive features.
The core was tuff, apparently identical with that in the cliffs to the east. It even contained fossils.
"I guess this whole dig might as well be taken over by the paleontology department," Lampert commented finally. "I suppose they'll at least want to compare fossils in the tilted and level strata."
"I suppose so." Mitsuitei was turning the little cylinder over and over in his hand. "Tell me, Rob, what's this little speck of green?"
"Copper salts of one sort or another, I suppose." Lampert was not greatly interested. "A lot of secondary minerals form in and under volcanic detritus. On this world, carbonates like malachite should form quite readily."
"Why should it form in a regular thread like this?"
"You mean a vein? Hard to tell precisely. Varying rates of water seepage, varying degrees of oxygen or carbon dioxide penetration, varying degrees of compactness in the rock where the stuff is formed—"
"I don't mean a vein. This is in a cylindrical body going right through the core from one side to the other, as though there had been a copper wire there originally which had been attacked by soil acids."
"Let's see. You're right. It's hardly an ordinary vein, though your suggestion seems a trifle far fetched. The paleontologists can probably furnish an idea. Maybe a vine or even a worm buried in the mud flow acted as the precipitating agent for copper salts in the subsequent seepage—I've seen beautiful fossils of pyrite which had been formed that way."
"But this shows no trace of structure, except for its exterior shape."
"Isn't a really well preserved structure the exception rather than the rule in fossils?"
"I suppose so. Still, I'd like to know just how far, and which way, this green thread goes. I'd also like to know whether there are dilute copper deposits spread through this rock, which could be concentrated in the way you suggest."
"The first could be learned by taking enough cores. The other would call for some very careful analysis of samples which had been selected with a very sedulous eye kept on the stratigraphy. You know that; you must have done that sort of thing looking for carbon-fourteen samples, at times."
"Yes, I see that. Could you make such analyses here?"
"No, except for the mere presence of copper. The cores would have to go back to a well equipped lab. Still, if you want to get them, it's all right with me. Problems were made to be solved. I'll admit this one doesn't seem very exciting to me, but I can use your data after you finish for work of my own. You should wind up with material for a pretty complete geochemical picture of this neighborhood. Shall I get the cores for you?"
"Yes, please."
"Silly question. All right." The mole was drawn up a short distance, and sent questing downward once more at an angle to the original shaft, branching off a short distance above the level from which the copper deposit had come. Again and again the process was repeated, each time at a slightly different bearing from the central hole; and Mitsuitei examined each core for traces of green. At last he found it, piercing the little cylinder of rock as the other had done; and then, at his suggestion, Lampert reset the mole to get a sample in the opposite direction from the one which had furnished the new specimen.
This also checked positive; and four more samples, taken along the same line at various distances, all did the same.
Apparently the line of green extended for some distance, about parallel both to the surface of the ground and the trend of the joint in which it was buried. Mitsuitei was radiant.
"I'm going down to that level if I have to come back with an expedition of my own! If that's a fossil worm, it's worth getting the whole length anyway—but I don't believe it is. I—"
"That will take a lot of time, you know," Lampert pointed out mildly.
"Certainly I know! Even if I use your fast excavator down to the tuff level, I'll have to do detail work from then on. What of it?"
"Well, the others may have jobs they want to do—"
"Then they can do them! What are we here for, anyway? I thought it was to investigate the past of this planet! Ndomi and Hans are doing that their own way right now. Why can't I? I'm an archaeologist, and I came along to do any archaeological work that presented itself to do; this is the only thing of the sort anyone's seen so far. I know what you're thinking. Maybe you're partly right. I certainly won't bet any money that this thread of green is a fossil telephone wire; but it's as likely to be that as anything else you've suggested, and I'm going down to that level and sift the whole volume. Hans and Ndomi can have any fossils I find if that will make you happier—and if one of them says he has no use for fossils he didn't dig himself, I'll make him eat his words. I can identify, locate and report on anything that turns up in a rock as well as any of those jigsaw-puzzle people; and I can do it in mud, too, which is more than any of them could manage."
"Don't get hot under the collar. If you can help it on this planet. You sound as though one of the boys had been giving you a lecture on the importance of knowing what strata a given series of specimens represent."
"Not one of our boys—they have a little more sense. But there was a young paleontologist when I was covering the Antares worlds whose memory still makes my blood pressure go up. Never mind me; that's not important. But I want to make this dig."
"It will tie up machines, however freely we can spare time," Lampert said slowly. "I'll tell you: how about this? We spend the rest of the day getting cores from other points along these cracks. For one thing, we ought to know more about the structure of the hill, and for another, we might find more of your 'wires.' After all, the chance of our hitting the only one around is pretty remote. I can't quite see a single dropped piece of copper wire showing up in the first two days of a project like this."
"I neither said nor implied that this should be the only piece. I don't doubt for a moment that there are others, whether they are wires or worms."
"Sorry. Well, we take these cores back to camp this evening, together with any others we find of the same sort, and let Hans and Ndomi look them over. If they don't turn out to be something that the boys recognize and can classify right off the bat, we come back tomorrow with all the digging machinery you want, and dig until you either find all you want, satisfy yourself that there's nothing here or find something which obviously requires more specialized attention than we can give it. All right?"
"Nothing could be fairer. Let's go!"
The discussion in camp that evening was animated beyond anything the guide had heard. His original estimate of these men as relatively quiet specimens underwent a sharp revision. Mitsuitei's report of the day's activity at his site had, it is true, been delivered quite calmly; but from then on matters grew progressively livelier. This was not caused by opposition to the archaeologist's plans. The others were all in favor of remaining, for their own reasons. However, the question of just what was likely to be found gave rise to much rather barbed comment on Sulewayo's part. "I don't see how you can expect to find any trace of civilized work here," he said flatly at one point. "The animal and plant life of this planet is at a stage of evolution corresponding to something like Earth's Pennsylvanian age, when the amphibians were the highest known forms of life. I'm not saying that there couldn't be such a thing as an intelligent amphibian. But I do say that the normal set of evolutionary forces which, on both Earth and Viridis, produced creatures of the amphibian pattern could have done thatorproduced an intelligent fish; not both. If the latter ever evolved, it failed; for the amphibians—pardon me, amphibids—are here. To get an intelligent amphibid on this world will—or would, if the sun were to last long enough—require another orogenic period with the accompanying climatic changes. Then you'd stand a considerably higher chance of getting reptiles instead, if the comparative work done on over four hundred planets carries any meaning."
"I don't doubt the value of the work at all. You are very probably correct. It did not occur to me to expect remains of intelligent amphibians. I saw no reason to pre-suppose that anything in the way of artifacts which I might find would necessarily be native to this planet."
"You think there were other visitors from outside the Beta Librae system?"
"The possibility certainly exists. Here we are."
"But for Pete's sake! Do you really expect that they stayed long enough to build a city, or do you think you have the remains of a camp like ours, or what?"
"I don't think anything. It has been suggested that such people did come, and stayed long enough to—"
"And you think you've found them."
"I think nothing, except that I have found, with Rob's help, something which neither his professional knowledge, nor mine, nor even yours, is able to explain; and I think an explanation is desirable. I hope you won't consider me discourteous for pointing out that each time you have tried to accuse me of jumping to conclusions, you have been able to do so only by jumping to some yourself. I might further add that the suggestion that this planet had been stocked with its present supply of life types by visitors from space was advanced by a paleontologist, not by one of my colleagues. I gather he could not understand how life could evolve to the state it shows in the thirty-odd million years that the planet seems to have been solid. I neither support nor deride the idea; I simply want to gather data, in an attempt to explain a much simpler question—why are narrow threads of copper compounds to be found every few feet in the volcanic tuff filling the joints in a certain limestone hill, and why are those threads always nearly horizontal? You and Hans say they are not organic fossils, and I accept your conclusion. Rob says that there is no copper in that rock, detectable with his equipment, except within a few millimeters of the green threads. I say nothing except that I have never seen such a thing before. Under the circumstances, I fail to understand where you get the idea that I think there is a city built by the people who stocked this world thirty million years ago buried under that hill. I know I said 'city' when I first saw it, and I still think I was justified in the opinion; I have now seen evidence which causes me to admit that the vegetation pattern was not caused by artificial structures, and I dismiss the original hypothesis. I still want to dig there, and in accordance with Rob's agreement I am going to dig there, with the assistance of anyone who chooses to help. I know you want to go back to your set of leg bones in the cliff, and have no objection to your doing so. Even I can now see, on the basis of your description, that you are uncovering the fossil of a land animal; and I agree that it is of great importance to get it out intact, if possible. But if I can see the importance and even the nature of your work, why can't you do the same for mine?" The little man was leaning forward and staring intensely into Sulewayo's face by the time he finished this harangue, and Ndomi once more felt a trifle ashamed of himself. Lampert, however, saved him the need of formulating an apology.
"I'm sure Ndomi didn't mean to ridicule your work in any way, Take," he said. "We all realize perfectly that an underground phenomenon which cannot be explained at sight either by geology, paleontology or archaeology is something which requires investigation. I imagine that the best plan will be for String and me to go with you tomorrow, while the others continue their stone-cutting. Hans, just how far along are you, anyway?"
The older paleontologist thought for a moment.
"We don't really know," he said at last. "Of course, we aren't trying to get the individual bones completely free of the matrix; that will take somebody months or years. We're uncovering just enough to determine the extent of the specimen, so we can take it all out in one block—or more, of course, if it's too big. So far we can only guess at how big it is. We've uncovered with certainty two feet, and gone about half a meter along one of the attached legs. They seem to be extending straight back into the cliff, so in effect we're cutting a tunnel beside the thing. Assuming it had two main leg sections, as most of the present animals on both Earth and Viridis appear to have, we're about halfway between knee and hip joint. Of course, it might turn out to be the Viridian equivalent of a horse or chicken. In that case, we're about half way between ankle and knee. We certainly have several feet yet to penetrate before we can outline the whole block, assuming that the specimen is essentially complete. Several days, I would guess."
"Can you use any sort of power apparatus for any of your cuts?"
"I don't like to, on general principles, but—yes, we could, with actually very little risk. If you have some sort of rock saw whose cutting part can get fine control, I'd be willing to use it for parts of the tunnel away from the actual specimen."
"I have. We'll take you up there first thing in the morning, and I'll go down with you and show you how to use it before going on with Take and String."
"Who holds the 'copter in place while you climb down the ladder, give your lesson and come back?" asked the guide.
"Hmph. I forgot about that. All right, I'll break out the machinery and give the lesson right now." He got up and strode to the helicopter. McLaughlin covered him from the fence to the aircraft, but nothing dangerous appeared. The geophysicist disappeared inside, and returned a moment later with a compact metal case under his arm. The guide holstered his weapon as the gate in the fence closed once more....
Actually, the Felodon was miles downstream. It had spent the day in its chosen lair, apparently indifferent to the doings of the men a few hundred yards away. With the coming of darkness—real darkness this time, for the rain clouds cut off both the moonlight and the night glow from the upper atmosphere—it had emerged, hunted, killed and fed as before, apparently unhampered by the lack of light. By midnight it was back in the same lair, paunch distended, as close to sleep as its coldblooded kind ever came.
VI
The rain was still falling when the clouds lightened once more to the rising sun. Lampert was getting used to navigating the canyon by radar, and was an excellent pilot anyway; so he did not have too much trouble in locating the shelf where Sulewayo and Krendall had been working. Getting the men down to it was not particularly difficult, though rather nerve-racking. Krendall went first, unburdened except for his personal equipment. Then he steadied the ladder for Sulewayo who had the cutter strapped across his shoulders. The steadying hand was needed. Climbing down a rope ladder when loaded "top-heavy" can be an extremely awkward bit of activity. Had the pilot above been any less capable, it would probably have been impossible.
The ledge was wet, but fortunately not particularly slippery. The men set their equipment on the ground at the point where their cut entered the crack in the cliff, and without delay set to work. The tunnel was deep enough now to shelter the one actually cutting from the rain, so at first they took turns at this operation.
The cutting machine Lampert had provided was a sort of diamond-toothed chain saw capable of a two-meter extension. Ordinarily it was not the sort of thing a paleontologist would consider using so close to a specimen; but the men were fairly sure by now of the general extent of the thing they were uncovering. Even so, they used the saw only on the side of their tunnel away from the visible remains. They speedily widened the passage enough to permit them both to get inside and work on the face of the exposed material; but they still used hand tools whenever there was any suspicion that a bone might be about to appear. Work proceeded several times as fast as it had the day before.
They tried cutting another tunnel on the opposite side of the fossil, but this proved rather awkward. The creature was close to this side of the crack, and they had to cut limestone as well as the softer tuff. The saw proved capable of handling this—it would have handled granite without trouble—but went a little more slowly. Eventually, however, the two men were working on opposite sides of the fossil, each in a tunnel extending some two meters into the cliff face.
Half a day's work uncovered the leg bones sufficiently to show that Krendall's first idea had been right. There were only the two major joints, each a trifle shorter than the corresponding parts of the human skeleton. The lower leg was single rather than double, however; knee and ankle both consisted of ball-and-socket joints; and with this fact determined the men paused for thought.
"Now why," mused Krendall aloud, "should any sort of creature need that articulation?"
"Could that foot be a hand instead?" asked Sulewayo.
Of course, questions like that should have awaited the results of detailed examination in a laboratory. Equally of course, the two men proceeded to clear one of the "feet" a little more thoroughly in order to find out for themselves. The answer was not helpful, though.
"He might have picked up a twig with it, but he couldn't have held it any more tightly than I can in my toes," was Krendall's verdict. "It's a bigger and flatter foot than ours. But it's a foot—nothing more."
"Maybe a swimming organ on the side?" suggested Sulewayo cautiously.
"Seems doubtful. If that joint evolved for such a purpose, I should think there'd be a corresponding modification in the foot bones, too—say a flattening such as you see in the paddles of some of the Mesozoic sea reptiles of Earth."
"Reasonable."
"But not necessarily right. That I admit. Anything else strike you?"
"Yes, though it makes the joints still more unbelievable."
"What?"
"The foot itself. Unless some rather remarkable distortion has occurred, it had both longitudinal and transverse arches, like yours and mine—which suggests strongly that this thing's ancestors had been walking erect on two legs for some hundreds of thousands of generations." Krendall raised his eyebrows at this, and silently examined the bony structure before them for several minutes.
"I—hadn't—spotted—that," he said slowly. He looked in silence for several more seconds. Then the two men, moved by a single thought, went to the other end of the exposed leg and began to clear the hip joint and pelvic region. They worked almost in silence, understanding each other perfectly, like an experienced surgical team; and gradually the equivalent of a pelvic girdle and lower end of a spinal column were cleared sufficiently to show their general nature.
It was at this point that the helicopter returned; but neither man noticed the fact until McLaughlin had called several times from the open ladder hatch. They climbed silently and thoughtfully up to the flyer; but Mitsuitei's first question started the talk flowing.
It did not end for a long, long time.
Krendall, with difficulty, held interruptions of his more volatile companion.
"There can be only the slightest doubt that this thing we're uncovering walked erect on two legs," he reported. "The feet; the way the pelvis is modified tosupportinternal organs; the fusing of the lowest vertebrae with the pelvic girdle to form a weight carrying foundation—they all point the same way. The only thing hard to understand is the knee and ankle joints. If we had them, it would be virtually impossible for us to hold our legs rigid. Perhaps some really remarkable musculature—"
"Or a cartilage structure which has not been preserved," cut in Sulewayo.
"Or some such thing as that, would explain it. I don't know. The creature is good for several Ph.D. theses just as it lies—and probably an equal number of nervous collapses when we get it out."
"I find myself strongly desirous of seeing its skull," remarked Lampert. Sulewayo glanced at him sharply.
"You, too?" asked the young paleontologist. "I was hoping I was the only one crazy enough to have thought of that." Mitsuitei smiled openly, an almost unheard-of act for him. He said nothing for a moment, but everyone saw him; and even McLaughlin understood the thought. After a sufficiently long pause, he asked a question.
"Have you uncovered enough of this creature's structure to guess at any evolutionary connection—or lack of it—with the amphibids we already know on this world?"
"I'd hate to take any oaths," replied Krendall. "The legs, which we've seen most of, are different in detail; but they at least correspond in general with what we find here. The only really significant point there would be the single shin-bone. In that it resembles Viridian land life in general—these animals don't have the separate tibia and fibula characteristic of the usual run of Earthly land vertebrates. It really proves nothing about what we're all thinking, of course."
"I am tempted to work with you gentlemen tomorrow," muttered the archaeologist.
"Why? Didn't your investigation pan out?"
"It is harder for me to say than for you, so far. To dig a pit, big enough not only to work in but to cover a useful amount of ground, in a driving rain, is quite a job even with Rob's machines—which I would never use were I not sure that there is nothing of importance above the limestone level. I have gotten down to the rock over an area three meters square, which is very good going; but I shall undoubtedly find the pit full of water tomorrow, as we have not yet improvised a really satisfactory drainage system. I cannot—or at least will not—use machines inside the crack in the limestone; so it will be some time before I get down to our mysterious green threads."
"Then it would seem that the best we can do is go on as we have," said Lampert. "The only change might be if one more man were to help at Take's dig. But I don't suppose either Hans or Ndomi would care to leave his own job at the moment, and actually there's not much more to do at the hill which can be done by anyone but Take himself. I'll continue to help him as long as it's a question of moving mud, but after that he'll have to do his own sifting. String is automatically on guard duty at the hill, so there's not much change we can make. Though I must say I haven't seen anything dangerous yet, in that jungle."
"Those animals are like crows," remarked the guide. "We used to have 'em on the farm, back on Earth. They'd be all over a freshly planted field, while no one was around. Come out yelling—they don't move; come out with a gun, and they're gone—unless you'd happened to forget to load it; then they sat and laughed at you. If you're suggesting, Doctor, that I should relax the guard duty and lend a hand with digging, I veto the idea—and not because I'm afraid of getting my hands dirty."
"I won't say I didn't have some such thought, but I accept your ruling," smiled Lampert. There was silence for a moment; then Krendall reverted to the earlier subject.
"You know," he said, "if this thing we've found does turn out to have been intelligent, it will hardly solve any of the existing problems about Viridis."
"Why not?" asked Sulewayo in some surprise.
"We still won't know whether it's native to the planet or not, unless we can establish a relatively complete evolutionary sequence leading to this form. If we do that, the question of speed of evolution here gets worse than ever; if we don't no one will be sure whether or not we ought to look for buried spaceports or send out expeditions to find the planet they might have come from."
"The latter would be something of a waste of time," remarked McLaughlin. "Hunting one planet in the galaxy is like hunting one log of wood on Viridis." No one contradicted this. All had seen the galactic star clouds from outside planetary atmosphere.
"It seems to me, speaking as an amateur in your fields, gentlemen," said Mitsuitei, "that the mere discovery of an intelligent creature in the Viridian fossil deposits would, on the basis of our present knowledge of the mechanisms of evolution, strongly support the idea that this world was stocked from others. I realize that our knowledgemaynot be sufficient to justify us in that conclusion. But it iscertainlynot great enough to justify any other."
"You seem to have something there, Take," admitted Krendall. "If this thing does turn out to have room for a brain in its skull, I suppose the next ten conventions of the Interstellar Archaeological Society, or whatever you call it, will be meeting at Emeraude."
"I shouldn't be at all surprised. So far, my profession and yours have not overlapped, due to a considerable factor of difference in the time spans covered. But it is just possible that we would be holding joint meetings, in the event you describe."
"This meeting is changing from discussion to speculation," Lampert said drily. "I would be the last to decry the value of imagination; but actually we are as likely to face the need for entirely new hypotheses as the result of our work here, as to find support for any now in existence. I can speculate with the best of you, but for goodness sake let's not take any speculation too seriously. I don'treallybelieve that some big-headed descendants of Ndomi's fossil are listening in on me right now!"
Even Sulewayo admitted that this was rather unlikely, and the conversation turned to other matters until darkness fell.
No one had trouble sleeping. The loud drumming of the rain on the metal roof meant nothing to field workers with their experience. If anything, the sound was soothing, giving a perpetual reminder that there was a roof. Such protection is not always available, in that line of work....
The Felodon seemed to have lost its traveling propensity. Once more it went out into the utter darkness solely to get a meal. It accomplished this as quickly as ever, though its eyes must have been useless and the hiss and rumble of falling water drowned and buried any sounds which would have been useful in tracking. Back in the same lair, full-fed, it drowsed once more.
VII
Mitsuitei had been almost right in his prediction that the pit would be full of water. Only the fact that the land sloped a trifle—they were not right on top of the little hill—had saved it. As it was, several feet of water were in the bottom, and a good deal of mud had washed in from the two sides facing the edges of the crack. The other two, much better braced by deep-reaching roots, had held firm.
After some thought, Lampert used the little robot again. He started it at the bottom of the pit on the downhill side and drove almost horizontally toward the river. The two hundred meters of "neck" permitted the mole to emerge from the slope farther down. When it was withdrawn, a small drain hole was obtained. Several more of these were drilled, and the pit lost its water fairly rapidly.
There was still the problem of getting into the crack itself, which of course would involve digging below the level of the drain holes. Lampert, using the same excavator which had made the pit itself, finally provided a fair solution by digging a set of ditches around the larger hole; and since the opening itself was quite well protected by over-hanging trees, Mitsuitei had only drainage from the surrounding soil to contend with.
Two hours after arriving, therefore, he had a relatively clear working space. The bottom of the pit was limestone, exposed by the complete removal of the overlying soil, some three meters square. Across it ran the crack, a trifle less than a meter wide, still packed with dirt. Everything was muddy—limestone, projecting roots, and Mitsuitei himself. A slender log with branches cut to ten-centimeter stubs leaned against one corner, forming a rough ladder and giving entrance and egress to and from the site.
The machinery which had done the original digging was at one side. Mitsuitei did not expect to need it again. He was now equipped with a hand shovel, and seemed about to use it. Lampert, standing at the edge of the pit, felt the incongruity, but managed not to laugh.
"Are you sure there's nothing I can do down there with you?" he asked.
"I'm afraid not. From now on I want every bit of dirt to pass under my own eyes."
"Are you going to try to throw it all up here as you finish?"
"No. That's the purpose of the extra pit area down here. I can get a long way down the joint, simply heaping the material on the rock. It's damp enough to pile quite steeply, too."
"How far down do you think you can get? The crack's rather narrow to work in, and you have three and a half meters to go before you hit tuff. That's going to be rough shoveling. I still think you could use the machine safely for a little way further, at least."
"No doubt I could, but I'm not going to. There's one thing I might use, though. If you have another of those saws, such as the bonemen are using up on the cliff, I could widen this crack as I go—cut steps, in fact, to help get the mud up to this level when I'm further down."
"That's a good thought, but I don't have any other. If you really get far enough down to need it, though, I could fly up to get it. They were going to shift over to hand labor anyway."
"All right. Of course, it will be some time before I get that deep anyway; maybe I won't need it today." He bent to his work.
"But what do I do?" asked Lampert. "I can't go off to attend to my own projects, because String has to stay here to guard you. I can't get to the site where the others are working because I can't land there. I can't sit in the helicopter and twiddle my thumbs because I'll go crazy before the day is over." Mitsuitei straightened once more, and thought briefly.
"Is there nothing in the geophysical line you could do within sight of this pit?" he asked finally. "The saw and digging machine are not the only apparatus you brought."
"That's true. I brought some seismic gear, though I didn't plan to use it quite like this. I might map the formations under this hill. The information will be usable, I should think, and the joints will give quite a calibrating job. It will keep me busy, anyway."
"Just a minute!" Mitsuitei looked a trifle perturbed. "Does that mean you're going to set off explosives around here? I want the sides of this pit held up by something better than roots, if you do."
Lampert chuckled. "No explosives," he said. "This is a nice little gadget with a robot like the core sampler. It puts out waves of any type desired from any depth down to two hundred fifty meters—a sort of subterranean sonar. You'll never know it's working. The wave amplitude isn't enough to feel." He turned toward the helicopter on the river bank below, and was starting to walk toward it when McLaughlin interrupted. The guide had heard the conversation, and his question was purely rhetorical.
"You weren't planning to walk down to the flyer alone, were you, Doctor?"
"Well, yes, as a matter of fact. After all, I won't be working; I can keep my eyes open as I go. You can see me for the greater part of the journey from here, too."
Rather to his surprise the guide approved this argument, after a moment's thought.
"All right. But please keep your gun in your hand as well as your head on a swivel. I'd prefer to have Dr. Mitsuitei come down with us so we could stay together, but I know how he'd react to the interruption, and I realize you're not a kid. Just be careful."
Lampert promised; and the guide's manner had impressed him to the point where he was almost afraid to make the return journey, after reaching the flyer and packing his new equipment. He was rather surprised to get back to the site without being attacked, and McLaughlin's very evident relief at seeing him did nothing to ease his feelings.
He began to set up the machinery. This consisted of an assembly very similar to the drilling mole—a small delving robot drawing a slender tail behind it, the tail wound on a drum which surrounded the control unit. A dozen smaller cylinders reposed in attached clips.
"The attached borer," Lampert explained to the guide, "goes down to any depth I set, up to two hundred fifty meters. It can produce any of the three normal types of earthquake wave, singly or in any combination, with sufficient intensity to be detected at a range of over two kilometers in reasonably well-conducting rock. The small cylinders are detectors, equipped not only to receive and analyze the wave coming through the ground but to measure electronically their location with respect to each other and the main station. I can use as many of them as I please, up to the full dozen; but they can be planted only a little way below the surface. There exists equipment for getting readings at depths comparable to that of the transmitter, but I don't have it. As it stands, by spotting the receivers carefully I can get a pretty good picture of the formations for a radius of a kilometer and a depth even greater with ten minutes measuring—and ten hours computing."
"How far out do you plan to place these receivers?" the guide asked pointedly.
"Well—I hadn't made a detailed plan of that. I'd rather like to have them in radiating lines of three, the lines spreading about fifteen degrees, and the individual cylinders about two hundred meters apart."
"And just how were you going to place them? I gather that someone has to walk the best part of four kilometers—or do these things fly, in addition to their other abilities?"
"Er—someone walks. I thought perhaps, since you don't like the idea of my going alone through the jungle, that I might stand guard over Take in the pit while you set them out."
"Hmm." The guide did not explode, to Lampert's relief. It had not occurred to the scientist that the job of wandering around a hole in the ground waiting for animals which never came might get a little boring to a man of McLaughlin's background. "Let's go over first and see how Dr. Mitsuitei is getting along. I guess you could stand over him with a gun for half an hour. Of course, the cover runs dangerously close to the pit. Maybe we'd better burn it off to a safer distance—still, I guess that won't be necessary. You can stand out here where it's relatively clear, and see all the approaches to the pit. Something might jump in without your having time to hit it, and you'd at least see it and could get there fast enough to do any shooting necessary."
They approached the hole and looked in. Mitsuitei was working busily. A fair quantity of earth lay spread on the rock, and some two thirds of the length of the crack had been excavated to a depth of perhaps a quarter of a meter. The geophysicist attracted the little man's attention and told him of the plan; Mitsuitei nodded and bent once more to his work.
The Felodon was becoming restless. It could hardly be hungry as yet; but it was on its feet, snarling silently as it had when the helicopter first entered its ken. For perhaps a minute it stood; then, with the same air of determination it had shown days before and scores of kilometers away, it began to thread its way through the underbrush toward the river—and the digging site.
"I'll stand where you suggested, and never take my eyes off the pit," Lampert promised.
"Then I'll come back to find you missing," replied the guide. "You're guarding yourself too, remember. Don't keep your eyes on anything. Keep them moving."
He finished distributing the little cylinders in the various pockets of his outer clothing, and moved off in the direction Lampert had indicated. He looked back frequently, but each time saw the scientist alert. When the underbrush finally cut off the view, he refused to worry too much.
Actually, McLaughlin had gone to considerable pains to make the jungles of Viridis sound more dangerous than they really are. His conscious motive was to make the inexperienced members of the party alert enough for their own safety. It was quite true that a man could be killed in quite a variety of ways in those rain forests. There was a distinct possibility, however, that he also wanted to impress them with the importance of his services.
He did not, therefore, suffer much from anxiety during his walk, though on the other hand he wasted no time. He had, of course, only a rough idea of the distance he had traveled, though he was able to keep his direction with a small impulse-compass tuned to the seismic apparatus and forming part of its regular equipment.
He dropped three of the cylinders at the required intervals, as nearly as he could guess, forcing each a little way into the ground as Lampert had shown him; then he turned at right angles, walked what he hoped was the right distance and started back toward the site, planting equipment as he went. Out again, in again; and the last of the dozen tubes was in the ground.
Mitsuitei's shovel scraped deeper.
Lampert, glancing up and around every few seconds, made minute adjustments to the controls of his seismic apparatus. Its little mole robot had started on its downward trip.
The Felodon lurked thirty yards from the point where Lampert was standing, protected from his sight by the undergrowth and by one of the piles of dirt thrown up by the machine which had dug the pit. It seemed to be looking through the soil at the spot where the man was. The snarl was still on its face, but no muscle moved in its long body. It had been there for minutes without moving; it had frozen similarly when McLaughlin had passed it on his way out. Now it simply stood and waited.
On a cliffside kilometers away, Ndomi Sulewayo gave utterance to the first profanity Krendall had ever heard him use. They were on opposite sides of the block containing the fossil, so neither could see the other. Krendall, naturally, asked what was wrong.
"Don't tell me a bug got through one of these suits!"
"Worse, if possible. I told you this foreleg—" both had been carefully avoiding the use of such words as "arms"—"was sticking out sideways, so that I was afraid we might have cut off part of it in digging the tunnel."
Krendall nodded. "I remember. Did we?"
"I don't know."
"Eh? How come? I should think there'd be no doubt, one way or the other, if you have that much of the limb clear."
"Well, I haven't. I got as far as the bone goes—and right there I run out of tuff and into the limestone. If there's anything more, it's in an entirely different kind of rock, which is a trifle unlikely; but I'm going to have to check the blocks we cut from this part of the tunnel in order to make sure, and I don't look forward to the job at all." Krendall, properly sympathetic, came around to Sulewayo's side to look, and agreed that the search was necessary. The bone the younger man had been clearing ended in a joint of the type they had come to regard as typical of the creature's limbs; and this had occurred almost exactly at the surface they had left when first outlining the block with the saw.
Sulewayo, with a grunt of disgust, dropped his tools and went out into the rain, where the blocks cut from the cliff had been piled; Krendall, nobly sacrificing his personal inclinations, went along with him.
The search lasted for a long time; for a long time, in fact, after it became evident that it was going to be useless, for the chance of a perfect specimen is not easily thrown away. Finally, however, Krendall straightened up with a sigh.
"I guess we'll have to be satisfied with a restoration on one side," he said wearily. "I hope someone fifty years from now doesn't find another and discover that it's a sort of vertebrate fiddler crab, with one fore-limb ending in a paw or claw something like five times the size of the one on the other."
Sulewayo gave a gloomy assent, and the two went back to work in their respective tunnels.
Lampert saw McLaughlin the instant the underbrush made it possible, a fact which the guide later admitted was to the scientist's credit. He had, of course, been eagerly awaiting that return, for the transmitter was down to its first set depth and awaiting only the word that all receivers were in place. He called eagerly the moment the guide came within earshot.
"Everything down?" McLaughlin nodded.
"Everything down, as nearly as I could tell the way you said. How long will the readings take?"
"Only a few minutes. I'll take a couple of calibration shots from ten, fifteen and twenty meters' depth; then ones at fifty, a hundred and so on down as far as the mole will go. The shooting takes practically no time. It's the drilling that will hold us up."
"What then?"
"Well," Lampert smiled, "after that the usual procedure is to pick up the receivers and place them in a similar pattern in a new direction. If the field crew doesn't go on strike, we take the whole circle about the transmitter."
"I was afraid of that," grunted McLaughlin, as he stopped by the machine. "Well, let's go." The two men bent over the controls in a silence broken only by the scraping of Mitsuitei's shovel a dozen meters away. Lampert pressed his shot button, and a light on the panel flashed white momentarily. Below their feet, unfelt, the pulse of sound energy raced outward, echoing from the walls of deepstriking joints, from the boundaries between rocks of differing densities or elastic constants, from the walls of caverns deep in the limestone; some tiny portion of the energy from time to time encountering and affecting one of the tiny receivers McLaughlin had buried.
As each receiver gathered its bit of data, it retransmitted the information to the master unit; and everything was recorded on a single sheet as the milliseconds sped by. Long before a full second had passed, the first of the pulses had damped out as heat energy, and enough had been transmitted for the machine to obtain an adequate averaging record. The light blinked out again. Lampert nodded in satisfaction, and sent the mole downward once more.
"Look, good. Now the next set," he remarked.
As that pulse of seismic energy went forth, the Felodon rose to its full height, almost showing itself over the pile of dirt which was now its sole protection from the view of the men. The snarl on its face seemed to grow fiercer, if that were possible. For just an instant it seemed torn by conflicting desires. But that was for just an instant; any tendency to flee was smothered before it could take full form. There were two men now to worry about, and correspondingly less chance for the opportunity it had been awaiting. But the opportunity came. For just a moment the guide looked down at the panel which was absorbing Lampert's full attention. In that moment a green-and-lavender streak flowed over the heap of soil in a single leap and vanished into the pit. It must have been timed and guided by the mysterious sense McLaughlin had mentioned. It could see none of the men when it leaped, yet it timed the act for the moment none were looking, and landed directly on Mitsuitei.
The little archaeologist never knew what hit him. He died without a sound, and the killer, as though nothing lived anywhere in the neighborhood, settled down to its meal.
In this it must have been disappointed. The chemicals in the clothing designed to repel Viridian insects were equally obnoxious to the carnivore, and it made no serious attempt to get through them. However, not all of the body was protected in this way....
A second pulse went from the buried transmitter, and then a third, each from a point a few meters deeper than the last. Lampert's attention, of course, was centered on his controls. McLaughlin's eyes were once more sweeping restlessly over the surrounding landscape. Both heard the sounds coming from the pit, but neither interpreted them as anything more than the scraping of Mitsuitei's shovel. Neither, of course, considered them consciously. Their attention was finally attracted by something decidedly more noticeable.
The Felodon did not—or could not?—remain at its meal for more than a few moments. Its apparent indifference to the other men changed once more to what seemed like an internal struggle. An observer would have been sure, up to now, that it was using its peculiar sense to avoid the sight of men with guns; but that hypothesis failed now.
As Lampert started the mole robot downward once more, the Felodon leaped out of the pit toward the two men—regardless of the fact that McLaughlin was facing toward it.
VIII
McLaughlin saw the fanged head emerge, and his reflexes took over instantly. A streak of flame passed beside the leaping carnivore, exploding into a white-hot blossom of blazing gas as it contacted the pile of dirt on the far side of the pit. The guide ducked and rolled frantically sideward as another spring carried the creature toward him. Claws raked the air past his shoulder, and he fired again before the roll was complete and without any sort of aim.
Men and beast alike were spattered with white-hot droplets of metal from the seismic recorder as the second shot caught it squarely; and this seemed to be enough for the carnivore. Its next leap was away from the men instead of toward them. A geyser of steam and mud erupted beside it as Lampert finally got his weapon into action, and before the vapor had been beaten down once more by the rain the animal was out of sight behind the undergrowth. Both men sent several shots in the direction of the crackling bushes, but accomplished nothing except the felling of a tree or two and the starting of a bonfire which failed to make any headway against the rain.
Convinced that the Felodon had gone, the men ran to the pit. Lampert did not even take time out to glance at the wreckage of his equipment. There was just enough distance to cover to let each one realize that he had no idea how long the carnivore had been inside, and what the "scraping" sound might have been. Both slowed down as they approached the edge, not relishing what they expected to see. But this did not prove to be what they had expected. McLaughlin's face, already grim, turned gray as he saw that his first shot had not merely missed the animal at which it was aimed.
The bolt had struck the pile of dirt which had been left by the digging machinery at the far lip of the pit, and scattered most of it to the four winds. Perhaps half a ton had slid back into the hole from which it had originally been removed. There was no telling, from above, what the Felodon had done to Mitsuitei. The upper half of the archaeologist's body was buried completely, and the rest so liberally sprinkled with dirt that it was not at once identifiable.
The guide, using language strange even to the widely-traveled Lampert, leaped the three meters downward without bothering to use the ladder, seized a projecting leg and tried to draw the little man clear of the soil. Lampert, equally aware of the possible value of time but feeling that he would do little good with a broken leg, made the descent in the normal manner.
By the time he reached the bottom, McLaughlin had succeeded in dragging Mitsuitei almost completely clear. Lampert started forward to clear the mud from the still hidden face; then he stopped, and his stomach abruptly heaved, as he realized that the face was not hidden.
It was gone.
Mitsuitei had removed the head-gear and gloves from his protective suit for the normal reason—to see and manipulate better. The exposed head and hands had formed the Felodon's hasty meal.
The paleontologists saw the helicopter approaching this time, for they were working outside the tunnel. Between them on the ledge lay a block of stone some five feet long, two high and four wide—over two tons of material, all told, which had been worked out of the hole rather ingeniously by the men. Partial undercuts had been made, rollers worked out of stone by the cutter placed underneath, and the undercutting completed along a plane which sloped slightly upward into the tunnel. Of course the block had run off the rollers once it was out in the open, and the men could no more shift it another centimeter than they could return to Emeraude without the helicopter; but at least it was more or less accessible by air. They were chipping waste rock from the corners when the flyer appeared.