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 to support internal 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 knowledge may not be sufficient to justify us in that conclusion. but it is certainly not 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't really believe 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.