There were no means known to Tommy of reckoning time in that strange place of twilight. His watch had been broken in the airplane fall; and Dodd never remembered to wind his, but they estimated that about two weeks had passed, judging from the number of times they had slept and eaten.
In those two weeks they had gradually begun to grow accustomed to their surroundings. Haidia, the girl, had arrived on beetle-back within an hour after Bram's departure, apparently into a cleft of the rocks—how he had communicated his order to the beetle steeds Tommy had no idea. And under the girl's ministrations Dodd was making good progress toward recovery.
That Haidia was in love with Dodd in quite a human way was evident. To please the girl, both Dodd and Tommy had learned to eat the raw shrimps, which, being bloodless, were really no worse than oysters, and had a flavor half-way between shrimp and crawfish. To please the men, Haidia tried not to shudder when she saw them devouring the breadfruit and nectarines of which Bram always had a plentiful supply. Bram was solicitous in his inquiries for Dodd's health.
"Jim, I've been thinking about our chances of getting away," said Tommy one morning. "It's evident Bram's only waiting for your recovery to put some proposition up to us. Suppose you were to feign paralysis."
"How d'you mean? What for?" demanded Dodd.
"If he thinks you're helpless, he'll be less on his guard. You haven't walked about in his presence." That was true, for the activities of the two had been nocturnal, when Bram had vanished. "Let him think a nerve's been severed in your neck, or something of the sort. If it doesn't work, you can always get better."
Dodd's realistic portrayal of a man with a partly paralyzed right side brought cries of horror from Bram next morning. Solicitously he helped Dodd back to the couch. Bram, when not under the influence of his drug, had moments of human feeling.
"Can't you move that arm and leg at all, Dodd?" he asked. "No feeling in them?"
"There's plenty of feeling," growled Dodd, "but they don't seem to work, that's all."
"You'll get better," said Bram eagerly. "You must get better. I need you, Dodd, in spite of our differences. There's work for all of us, wonderful work. A new humanity, waiting to be born, Dodd, not of the miserable ape race, but of—of—"
He checked himself, and a cunning look came over his face. He turned away abruptly.
At the end of two weeks or so, an amazing thing happened. One day Haidia, with a look of triumph in her eyes, addressed Dodd with a few English words!
Her brain, which had probably developed certain faculties in different proportions from those of the upper human race, had registered every word that either of the two men had ever spoken, and remembered it. As soon as Dodd ascertained this, he began to instruct her, and, with her abnormal faculties of memory, it was not long before she could talk quite intelligently. The obstacle that had stood between them was swept away. She became one of themselves.
In the days that followed the girl told them brokenly something of the history of her race, of the legend of the universal flood that had driven them down into the bowels of the earth, of the centuries-long struggle with the beetles, and of the insects' gradual conquest of humanity, and the final reduction of the human race to a miserable, helpless remnant.
Everywhere, Haidia told them, were beetle swarms, everywhere humanity had been reduced to a few handfuls. Bram, by breeding mankind from prolific strains, and using the new-born progeny for food, had temporarily averted universal starvation. But a new swarm of beetles was due to hatch out shortly, and then—
The girl, with a shudder, put her hand to her bosom, and brought out a little bright-eyed lizard.
"The old man you saw with me, who is one of our wise elders, has told our people that these things feed upon the beetle larvae," she said. "We are putting them secretly into the nests. But what can a few lizards do against millions." She looked up. "In the earth above us, the beetle larvae extend for miles, in a solid mass," she said. "When they come out as beetles, it will be the end of all of us."
Bram had grown less suspicious as the time passed. His sudden visits to the cavern had ceased. Dodd and Tommy knew that he spent the nights—if they could be termed nights—lying in a drugged slumber somewhere among the rocks. They had asked Haidia whether there was any way of escape into the upper world.
"There are two ways from here," answered the girl. "One is the way you came, but it is impossible to pass the beetle guards without being torn to pieces. The other—"
She shuddered, and for an instant drew back the film from across her pupils, then uttered a little cry of pain at the light, dim though it was.
"There is a bridge across that terrible monster that devours all it touches," she said, shuddering, meaning the fire.
Suddenly Dodd had an inspiration. He still had the fur coat that he had worn, and, reaching into a pocket he drew out a pair of snow goggles, which he adjusted over Haidia's nose.
"Now look!" he said.
Haidia looked, blinked and, with an effort kept her eyes open. She gazed at Dodd in amazement. Dodd laughed, and pulled her toward him. He kissed her, and Haidia's eyes closed.
"What is this?" she murmured. "First you give me medicine that opens my eyes, and then you give me medicine that closes them."
"That's nothing," grinned Dodd. "Wait till you understand me better."
Bram's eyes were preternaturally bright. It was evident that he had been increasing his dose of late, and that he was fully under the influence of it now.
"Well, gentlemen, the time has come for us to be frank with one another," he said, as the three were gathered about the little table, while Haidia crouched in a far corner of the cave. "I want you to work for me in my plans for the regeneration of humanity. The time for which I have long labored is almost at hand. Any day now the new swarm of beetles may emerge from the pupal stage. But before I speak further, come and see them, gentlemen!"
He rose, and Dodd and Tommy rose too, Tommy supporting Dodd, who let his arm and leg trail awkwardly as he moved.
Bram led the way into the cleft among the rocks into which he had been in the habit of passing. Beyond this opening the two men saw another smaller cavern, with a beetle guard standing on either side, antenna waving.
Bram shrilled a sound, and the antenna dropped. The three passed through. Tommy saw a hair-cloth pallet set against the rocks, a table, and a chair. Beyond was a sloping ramp of earth. Overhead was a rock ceiling.
Bram led the way up the ramp, and the three stepped through a gap in the rocks and found themselves on an extensive prairie. But in place of the red grass there was a vast sea of mud.
By the light cast by the petrol fire, which roared up in the distance, a veritable fiery fountain, the two Americans could see that the mud was filled with huge encysted forms, grubs three or four feet long, motionless in the soil.
Bram scooped up one of them and tossed it into the air. It thudded to their feet and remained motionless.
"As far as you can see, and for miles beyond, these pupae of the beetles lie buried in the decaying vegetation in which the eggs were hatched," said Bram. "Every century and a half, so far as I have been able to judge from comparative anatomy, a fresh swarm emerges. See!"
He pointed to the pupa he had unearthed, which, as if stirred into activity by his handling, was now beginning to move. Or, rather, something was moving inside the cocoon.
The shell broke, and the hideous head and folded antenna of a beetle appeared. With a convulsive writhing, the monster threw off the covering and stepped out. It extended its wings, glistening, with moisture, from the still soft and pliant carapace, or shell, and suddenly zoomed off into the distance.
Tommy shuddered as the boom of its flight grew softer and subsided.
"Any day now the entire swarm will emerge," cried Bram. "How many moultings they undergo before they undergo the finished state, I do not know, but already, as you see, they are prepared for the battle of life. They emerge ravenous. That beetle will fall upon the man-herds and devour a full grown man, unless the guards destroy it."
He raised his arms with the gesture of an ancient prophet. "Woe to the human race," he cried, "the wretched ape spawn that has cast out its teachers and persecuted those who sought to raise it to higher things!"
Tommy knew that Bram was referring to himself. Bram turned fiercely upon Dodd.
"When I joined the Greystoke expedition," he cried, "it was with the express intention of refuting your miserable theories as to the fossil monotremes. I could not sleep or eat, so deeply was I affronted by them. For, if they were true, the dasyuridae are an innovation in the great scheme of nature, and man, instead of being a mere afterthought, a jest of the Creative Force, came to earth with a purpose.
"That I deny," he yelled. "Man is a joke. Nature made him when she was tired, as the architect of a cathedral fashions a gargoyle in a sportive moment. It is the insect, not man, who is the predestined lord of the ages!"
And for once in his life, perhaps because at this point Tommy dug him violently in the ribs, Dodd had the sense to remain silent. Bram led the way swiftly back into the larger cave.
"When this swarm hatches out," he said, "I calculate that there will be a trillion beetles seeking food. There is no food for a tithe of them here underneath the earth. What then? Do you realize their stupendous power, their invincibility?
"No, you don't realize it, because your minds, through long habit, are only attuned to think in terms of man. All man's long history of slaughter of the so-called lower creatures obsesses you, blinds your understanding. A beetle? Something to be trodden underfoot, crushed in sport! But I tell you, gentlemen, that nature—God, if you will—has designed to supplant the man-ape by the beetle.
"He has resolved to throw down the wretched so-called intelligence of your kind and mine, and supplant it by the divine instinct of the beetle, an instinct that is infinitely superior, because it arrives at results instantaneously. It knows where man infers. Attuned closely to nature, it alone is able to fulfil the divine plan of Creation."
Bram was certainly under the influence of his drug; nevertheless, so violent were his gestures, so inspired was his utterance, that Tommy and Dodd listened almost in awe.
"They are invincible," Bram went on. "Their fecundity is such that when the new swarm is hatched out their numbers alone will make them irresistible. They do not know fear. They shrink from nothing. And they will follow me, their leader—I, who know the means of controlling them. How, then, can puny man hope to stand against them?
"Join me, gentlemen," Bram went on. "And beware how you decide rashly. For this is the supreme moment, not only of your own lives, but for all humanity and beetledom. Upon your decision hangs the future of the world.
"For, irresistible as the beetles are, there is one thing they lack. That is the sense of historic continuity. If they destroy man, they will know nothing of man's achievements, poor though these are. My own work on the fossil monotremes—"
"Which is a tissue of inaccuracies and half-baked deductions!" shouted Dodd.
Bram started as if a whip had lashed him. "Liar!" he bawled. "Do you think that I, who left the Greystoke expedition in a howling blizzard because I knew that here, in the inner earth, I could refute your miserable impostures—do you think that I am in the mood to listen to your wretched farrago of impossibilities?"
"Listen to me," bawled Dodd, advancing with waving arms. "Once and for all, let me tell you that your deductions are all based upon fallacious premises. No, I will not shut up, Tom Travers! You want me to aid your damned beetles in the destruction of humanity! I tell you that your phascalotherium, amphitherium, and all the rest of them, including the marsupial lion, are degenerate developments of the age following the pleistocene. I say the whole insect world was made to fertilize the plant world, so that it should bear fruit for human food. Man is the summit of the scale of evolution, and I will never join in any infamous scheme for his destruction."
Bram glared at Dodd like a madman. Three times he opened his mouth to speak, but only inarticulate sounds came from his throat. And when at last he did speak, he said something that neither Dodd nor Tommy had anticipated.
"It looks as if you're not so paralysed as you made out," he sneered. "You'll change your mind within what used to be called a day, Dodd. You'll crawl to my feet and beg for pardon. And you'll recant your lying theories about the fossil monotremes, or you die—the pair of you—you die!"
"I heard what he said. You shall not die. We shall go away to your place, where there are no beetles to eat us, even if"—Haidia shuddered—"even if we have to cross the bridge of fire, beyond which, they tell me, lies freedom."
High over and a little to one side of the petrol flame Dodd and Tommy had seen the slender arch of rock leading into another cleft in the rocks. They had investigated it several times, but always the fierce heat had driven them back.
Both Dodd and Tommy had noticed, however, that at times the fire seemed to shrink in volume and intensity. Observation had shown them that these times were periodical, recurring about every twelve hours.
"I think I've got the clue, Tommy," said Dodd, as the three watched the fiery fountain and speculated on the possibility of escape. "That flow of petrol is controlled, like the tides on earth, by the pull of the moon. Just now it is at its height. I've noticed that it loses pretty nearly half its volume at its alternating phase. If I'm right, we'll make the attempt in about twelve hours."
"Bram's given us twenty-four," said Tommy. "But how about getting Haidia across?"
"I go where you go," said Haidia, sidling up to Dodd and looking down upon him lovingly. "I do not afraid of the fire. If it burn me up, I go to the good place."
"Where's that, Haidia?" asked Dodd.
"When we die, we go to a place where it is always dark and there are no beetles, and the ground is full of shrimps. We leave our bodies behind, like the beetles, and fly about happy for ever."
"Not a bad sort of place," said Dodd, squeezing Haidia's arm. "If you think you're ready to try to cross the bridge, we'll start as soon as the fire gets lower."
"I'll be on the job," answered Haidia, unconsciously reproducing a phrase of Tommy's.
The girl glided away, and disappeared through the thick of the beetle crowd clustered about the entrance to the cavern. Tommy and Dodd had already discovered that it was through her ability to reproduce a certain beetle sound meaning "not good to eat" that the girl could come and go. They had once tried it on their own account, and had narrowly escaped the lashing tentacles.
After that there was nothing to do but wait. Three or four hours must have passed when Bram returned from his inner cave.
"Well, Dodd, have you experienced a change of heart?" he sneered. "If you knew what's in store for you, maybe you'd come to the conclusion that you've been too cocksure about the monotremes. We're slaughtering in the morning."
"That so?" asked Dodd.
"That's so," shouted Bram. "The beetles are beginning to emerge from the pupae, and they'll need food if they're to be kept quiet. We're rounding up about threescore of the culls—your friend Haidia will be among them. We've got some caged ichneumon flies, pretty little things only a foot long, which will sting them in certain nerve centers, rendering them powerless to move. Then we shall bury them, standing up, in the vegetable mould, for the beetles to devour alive, as soon as they come out of the shells. You'll feel pretty, Dodd, standing there unable to move, with the new born beetles biting chunks out of you."
Tommy shuddered, despite his hopes of their escaping. Bram, for a scientist, had a grim and picturesque imagination.
"Dodd, there is no personal quarrel between us," Bram went on. Again that note of pathetic pleading came into his voice. "Give up your mad ideas. Admit that the banded ant-eater, at least, existed before the pleistocene epoch, and everything can be settled. When you see what my beetles are going to do to humanity, you'll be proud to join us. Only make a beginning. You remember the point I made in my paper, about spalacotherium in the Upper Jurassic rocks. It would convince anybody but a hardened fanatic."
"I read your paper, and I saw your so-called spalacotherium, reconstructed from what you called a jaw-bone," shouted Dodd. "That so-called jaw-bone was a lump of chalk, made porous by water, and the rest was in your imagination. Do your worst, Bram, I'll never crucify truth to save my life. And I'll laugh at your spalacotherium when your beetles are eating me."
Bram yelled and shrieked, he stamped up and down the cavern, shaking his fists at Dodd. At last, with a final torrent of objurgation, he disappeared.
"A pleasant customer," said Tommy. "We'll have to make that bridge, Jim, no question about it, even if it means death in the petrol fire."
"Fire's dying down fast," answered Dodd. "Haidia ought to be here soon."
"If Bram hasn't got her."
"Bram got—that girl? If Bram harms a hair of her head I'll kill him with worse tortures than he's ever dreamed of," answered Dodd, leaping up, white with rage.
"You mean you—?" Tommy began.
"Love her? Yes, I love her," shouted Dodd. "She's a girl in a million. Just the sort of helpmate I need to assist me in my work when we get back. I tell you, Tommy, I didn't know what love meant before I saw Haidia. I laughed at it as a romantic notion. 'Oh lyric love, half angel and half bird!'" he quoted, beginning to stride up and down the cavern, while Tommy watched him in amazement.
And at this moment a complete beetle entered the cave. Complete, because it had a plastron, or breast-shell, as well as a back-shell, or carapace.
A double breast-shell! A new species of beetle? An executioner beetle, sent by Bram to summon them to the torture? Tommy shuddered, but Dodd, lost in his love ecstasy, was ignorant of the creature's advent.
"'Oh lyric love—'" he shouted again, as he twirled on his heel, to run smack into the monster. The crack of Dodd's head against the beetle-shell re-echoed through the cave.
The double plastron dropped, the carapace fell down: Haidia stood revealed. The lovers, folded in each other's arms, passed momentarily into a trance.
It was Tommy who separated them. "We'll have to make a move," he said. "I think the fire's as low as it ever gets. Why did you bring the shells, Haidia?"
"To save us all from the beetles," answered the girl. "When they see us in the shells, they will not know we are human. That is what makes it so hard to have to be eaten by those beetles, when they are such dumb-bells," she added, reproducing another of Tommy's words.
"Come," she continued bravely, "let us see if we can pass the fire."
The roaring fountain made the air a veritable inferno. Overhead the rocks were red-hot. A cascade of sparks tumbled in a fiery shower from the rock roof. Dodd, holding Haidia in his arms, to protect her, staggered ahead, with Tommy in the rear. Only the beetle-shells, which acted as non-conductors of the heat, made that fiery passage possible.
There was one moment when it seemed to Tommy as if he must let go, and drop into that raging furnace underneath. He heard Dodd bawling hoarsely in front of him, he nerved himself to a last effort, beating fiercely at his blazing hair—and then the heat was past, and he had dropped unconscious upon a bed of cool earth beside a rushing river.
He was vaguely aware of being carried in Dodd's arms, but a long time seemed to have passed before he grew conscious again. He opened his eyes in utter darkness. Dodd was whispering in his ear.
"Tommy, old man, how are you feeling now?" Dodd asked.
"All—right," Tommy muttered. "How's Haidia?"
"Still unconscious, poor girl. We've got to get out of here. I heard Bram yelling in the distance. He's discovered our flight. There may be another way out of the cave, and, if so, he'll stop at nothing to get us. See if you can stand, but keep your head low. There's a low roof of rock above us."
"There's water," said Tommy, listening to the roar of a torrent that seemed to be rushing past them.
"It's a stream, and I believe these shells will float and bear our weight. We've got to try. We've got to put everything to the touch now, Tommy. I'm going to lay Haidia on one of the shells, poor girl, and start her off. Then I'll follow, and you can bring up the rear."
"I'm with you," said Tommy, getting upon his feet, and uttering an exclamation of pain as, forgetful of Dodd's injunction, he let his head strike the rock roof overhead.
In the darkness he felt the outlines of his beetle-shell lying beside the torrent. He could hear Dodd in front of him, grunting as he raised Haidia's unconscious form in his arms and deposited her in her shell. Tommy got his own shell into the stream, and held it there as the waters swirled around it.
"Ready?" he heard Dodd call.
Before he could answer, there sounded from not far away, yet strangely muffled by the rocks, Bram's bellow of fury. Bram was evidently fully drugged and beside himself. Inarticulate threats came floating through the rocky chamber.
"Bram seems to have lost his head temporarily," called Dodd, laughing. "A madman, Tommy. He insists that the marsupial lion—"
"Yes, I heard you telling him about it," answered Tommy. "You handed it to him straight. However, more about the marsupial lion later. I'm ready."
"Then let 'er go," called Dodd, and his words were swallowed up by the sound of the hollow shell striking against the rocky bank as he launched his strange craft into the water.
Tommy set one foot into the hollow of his shell, and let himself go.
Instantly the shell shot forward with fearful velocity. It was all Tommy could do to balance himself, for it seemed more unstable than a canoe. Once or twice he thought he heard Dodd shouting ahead of him, but his cries were drowned in the rush of the torrent.
Suddenly a light appeared in the distance. Tommy thought it was another of the petroleum fountains, and his heart seemed to stand still. But then he gave a gasp of relief. It was a cluster of luminous fungi, ten or twelve feet tall, emitting a glow equal to that of a dozen 40-watt electric bulbs.
By that infernal light Tommy could see that the stream curved sharply. It was about fifty feet in width, and the low rock roof had receded to some fifteen feet overhead. Instead of a tunnel, there was nothing on either side of them but a vast tract of marshy ground thinly coated with the red grass.
As Tommy looked, he saw the shell that carried the unconscious body of Haidia strike the bank beside the phosphorescent growth. He could see the girl lying in the hollow of the shell, as pale as death, her eyes closed. Dodd was close behind. As the swirl of the current caught his shell, he turned to shout a warning to Tommy.
And Tommy noticed a singular thing, of which his sense of balance had already warned him, though he had hardly given conscious thought to the matter.The river was running up-hill!
Of course it was, since the center of gravity was in the shell of the earth, and not in the center!
But, again, the shell of the earth was under their feet!
Then Tommy hit on the solution to the problem. If the river was running up-hill, that meant that they must be near the exterior of the earth. In other words, they had passed the center of gravity: they must be within a mile or so of the exit from Submundia!
Tommy was about to shout his discovery to Dodd when his shell grounded beside the two others, at the base of the clump of fungi.
Huge, straight, hollow stems they were, with mushroom caps, and, like all fungi, fly-blown, for Tommy could see worms nearly a foot in length crawling in and out of the porous stalks. The stench from the growth was nauseating and overpowering, utterly sickening.
"Push off and let's get out of here!" Tommy called to Dodd, who was balancing his shell against the bank, and trying to peer into Haidia's face.
At that moment he caught sight of something that made his blood turn cold!
It was an insect fully fifteen feet in height, three times that of a beetle, lurking among the fungi. He saw a hugely elongated neck, a three-cornered head with a pair of tentacles, and two pairs of legs as long as a giraffe's. But what gave the added touch of horror was that the monster, balancing itself on its hind legs, had its forelegs extended in the attitude of one holding a prayer-book!
That attitude of devotion was so terrible that Tommy uttered a wild cry of terror. At the same time another cry broke from Dodd's lips.
"God, a praying mantis!" he shouted, struggling madly to push off his shell and Haidia's.
The next moment, as if shot from a catapult, the hideous monster launched itself into the air straight toward them.
(To be concluded in the February Number.)
Screaming, the guardsman was jerked through the air. An unearthly screech rang through the cavern. The unseen horror of Mammoth Cave had struck again.
Dr. Bird looked up impatiently as the door of his private laboratory in the Bureau of Standards swung open, but the frown on his face changed to a smile as he saw the form of Operative Carnes of the United States Secret Service framed in the doorway.
"Hello, Carnes," he called cheerfully. "Take a seat and make yourself at home for a few minutes. I'll be with you as soon as I finish getting this weight."
Carnes sat on the edge of a bench and watched with admiration the long nervous hands and the slim tapering fingers of the famous scientist. Dr. Bird stood well over six feet and weighed two hundred and six pounds stripped: his massive shoulders and heavy shock of unruly black hair combined to give him the appearance of a prize-fighter—until one looked at his hands. Acid stains and scars could not hide the beauty of those mobile hands, the hands of an artist and a dreamer. An artist Dr. Bird was, albeit his artistry expressed itself in the most delicate and complicated experiments in the realms of pure and applied science that the world has ever seen, rather than in the commoner forms of art.
The doctor finished his task of weighing a porcelain crucible, set it carefully into a dessicator, and turned to his friend.
"What's on your mind, Carnes?" he asked. "You look worried. Is there another counterfeit on the market?"
The operative shook his head.
"Have you been reading those stories that the papers have been carrying about Mammoth Cave?" he asked.
Dr. Bird emitted a snort of disgust.
"I read the first one of them part way through on the strength of its being an Associated Press dispatch," he replied, "but that was enough. It didn't exactly impress me with its veracity, and, from a viewpoint of literature, the thing was impossible. I have no time to pore over the lucubrations of an inspired press agent."
"So you dismissed them as mere press agent work?"
"Certainly. What else could they be? Things like that don't happen fortuitously just as the tourist season is about to open. I suppose that those yarns will bring flocks of the curious to Kentucky though: the public always responds well to sea serpent yarns."
"Mammoth Cave has been closed to visitors for the season," said Carnes quietly.
"What?" cried the doctor in surprise. "Was there really something to those wild yarns?"
"There was, and what is more to the point, there still is. At least there is enough to it that I am leaving for Kentucky this evening, and I came here for the express purpose of asking you whether you wanted to come along. Bolton suggested that I ask you: he said that the whole thing sounded to him like magic and that magic was more in your line than in ours. He made out a request for your services and I have it in my pocket now. Are you interested?"
"How does the secret service cut in on it?" asked the doctor. "It seems to me that it is a state matter. Mammoth Cave isn't a National Park."
"Apparently you haven't followed the papers. Itwasa state matter until the Governor asked for federal troops. Whenever the regulars get into trouble, the federal government is rather apt to take a hand."
"I didn't know that regulars had been sent there. Tell me about the case."
"Will you come along?"
Dr. Bird shook his head slowly.
"I really don't see how I can spare the time, Carnes," he said. "I am in the midst of some work of the utmost importance and it hasn't reached the stage where I can turn it over to an assistant."
"Then I won't bother you with the details," replied Carnes as he rose.
"Sit down, confound you!" cried the doctor. "You know better than to try to pull that on me. Tell me your case, and then I'll tell you whether I'll go or not. I can't spare the time, but, on the other hand, if it sounds interesting enough...."
Carnes laughed.
"All right, Doctor," he said, "I'll take enough time to tell you about it even if you can't go. Do you know anything about it?"
"No. I read the first story half way through and then stopped. Start at the beginning and tell me the whole thing."
"Have you ever been to Mammoth Cave?"
"No."
"It, or rather they, for while it is called Mammoth Cave it is really a series of caves, are located in Edmonson County in Central Kentucky, on a spur railroad from Glasgow Junction on the Louisville and Nashville Railroad. They are natural limestone caverns with the customary stalactite and stalagmite formation, but are unusually large and very beautiful. The caves are quite extensive and they are on different levels, so that a guide is necessary if one wants to enter them and be at all sure of finding the way out. Visitors are taken over a regular route and are seldom allowed to visit portions of the cave off these routes. Large parts of the cave have never been thoroughly explored or mapped. So much for the scene.
"About a month ago a party from Philadelphia who were motoring through Kentucky, entered the cave with a regular guide. The party consisted of a man and his wife and their two children, a boy of fourteen and a girl of twelve. They went quite a distance back into the caves and then, as the mother was feeling tired, she and her husband sat down, intending to wait until the guide showed the children some sights which lay just ahead and then return to them. The guide and the children never returned."
"What happened?"
"No one knows. All that is known is the bare fact that they have not been seen since."
"A kidnapping case?"
"Apparently not, in the light of later happenings, although that was at first thought to be the explanation. The parents waited for some time. The mother says that she heard faint screams in the distance some ten minutes after the guide and the children left, but they were very far away and she isn't sure that she heard them at all. At any rate, they didn't impress her at the time.
"When half an hour had passed they began to feel anxious, and the father took a torch and started out to hunt for them. The usual thing happened; he got lost. Whenhefailed to return, the mother, now thoroughly alarmed, made her way, by some uncanny sense of direction, to the entrance and gave the alarm. In half an hour a dozen search parties were on their way into the cave. The father was soon located, not far from the beaten trail, but despite three days of constant search, the children were not located. The only trace of them that was found was a bracelet which the mother identified. It was found in the cavern some distance from the beaten path and was broken, as though by violence. There were no other signs of a struggle.
"When the bracelet was found, the kidnapping theory gained vogue, for John Harrel, the missing guide, knew the cave well and natives of the vicinity scouted the idea that he might be lost. Inspired by the large reward offered by the father, fresh parties began to explore the unknown portions of the cave. And then came the second tragedy. Two of the searchers failed to return. This time there seemed to be little doubt of violence, for screams and a pistol shot were faintly heard by other searchers, together with a peculiar 'screaming howl,' as it was described by those who heard it. A search was at once made toward the spot where the bracelet had been picked up, and the gun of one of the missing men was found within fifty yards of the spot where the bracelet had been discovered. One cylinder of the revolver had been discharged."
"Were there any signs on the floor?"
"The searchers said that the floor appeared to be rather more moist and slimy than usual, but that was all. They also spoke of a very faint smell of musk, but this observation was not confirmed by others who arrived a few moments later."
"What happened next?"
"The Governor was appealed to and a company of the National Guard was sent from Louisville to Mammoth Cave. They took up camp at the mouth of the cave and prevented everyone from entering. Soldiers armed with service rifles penetrated the caverns, but found nothing. Visitors were excluded, and the guardsmen established regular patrols and sentry posts in the cave with the result that one night, when time came for a relief, the only trace that could be found of one of the guards was his rifle. It had not been fired. Double guards were then posted, and nothing happened for several days—and then another sentry disappeared. His companion came rushing out of the cave screaming. When he recovered, he admitted that both he and the missing man had gone to sleep and that he awoke to find his comrade gone. He called, and he says that the answer he received was a peculiar whistling noise which raised all the hair on the back of his neck. He flashed his electric torch all around, but could see nothing. He swears, however, that he heard a slipping, sliding noise approaching him, and he felt that some one was looking at him. He stood it as long as he could and then threw down his rifle and ran for his life."
"Had he been drinking?"
"No. It wasn't delirium either, as was shown by the fact that a patrol found his gun where he had thrown it, but no trace of the other sentry. After this second experience, the guardsmen weren't very eager to enter the cave, and the Governor asked for regulars. A company of infantry was ordered down from Fort Thomas to relieve the guardsmen, but they fared worse than their predecessors. They lost two men the first night of their guard. The regulars weren't caught napping, for the main guard heard five shots fired. They rushed a patrol to the scene and found both of the rifles which had been fired, but the men were gone.
"The officer of the day made a thorough search of the vicinity and found, some two hundred yards from the spot where the sentries had been posted, a crack in the wall through which the body of a man could be forced. This bodycrack had fresh blood on each side of it. Several of his men volunteered to enter the hole and search, but the lieutenant would not allow it. Instead, he armed himself with a couple of hand-grenades and an electric torch and entered himself. That was last Tuesday, and he has not returned."
"Was there any disturbance heard from the crack?"
"None at all. A guard was posted with two machine-guns pointed at the crack in the wall, and a guard of eight men and a sergeant stationed there. Last night, about six o'clock, while the guard were sitting around their guns, a faint smell of musk became evident. No one paid a great deal of attention to it, but suddenly for no apparent reason at all one of the men on guard was jerked into the air feet upwards. He gave a scream of fear, and an unearthly screech answered him. The guard, with the exception of one man, turned tail and ran. One man stuck by his gun and poured a stream of bullets into the crack. The retreating men could hear the rattle of the gun for a few moments and then there was a choking scream, followed by silence. When the officer of the day got back with a patrol, there was a heavy smell of musk in the air, and a good deal of blood was splashed around. The machine-guns were both there, although one of them was twisted up until it looked like it had been through an explosion.
"The Officer commanding the company investigated the place, ordered all men out of the cave, and communicated with the War Department. The Secretary of War found it too tough a nut to crack and he asked for help, so Bolton is sending me down there. Do you think, in view of this yarn, that your experiments can wait?"
The creases on Dr. Bird's high forehead had grown deeper and deeper as Carnes had told his story, but now they suddenly disappeared, and he jumped to his feet with a boyish grin.
"How soon are we leaving?" he asked.
"In two hours, Doctor. A car is waiting for us downstairs and I have reservations booked for both of us on the Southern to-night. I knew that you were coming; in fact, the request for your services had been approved before I came here to see you."
Dr. Bird rapidly divested himself of his laboratory smock and took his coat and hat from a cupboard.
"I hope you realize, Carnsey, old dear," he said as he followed the operative out of the building, "that I have a real fondness for your worthless old carcass. I am leaving the results of two weeks of patient work alone and unattended in order to keep you out of trouble, and I know that it will be ruined when I get back. I wonder whether you are worth it?"
"Bosh!" retorted Carnes. "I'm mighty glad to have you along, but you needn't rub it in by pretending that it is affection for me that is dragging you reluctantly into this mess. With an adventure like this ahead of you, leg-irons and handcuffs wouldn't keep you away from Mammoth Cave, whether I was going or not."
It was late afternoon before Dr. Bird and Carnes dismounted from the special train which had carried them from Glasgow Junction to Mammoth Cave. They introduced themselves to the major commanding the guard battalion which had been ordered down to reinforce the single company which had borne the first brunt of the affair, and then interviewed the guards who had been routed by the unseen horror which was haunting the famous cave. Nothing was learned which differed in any great degree from the tale which Carnes had related to the doctor in Washington, except that the officer of the day who had investigated the last attack failed to entirely corroborate the smell of musk which had been reported by the other observers.
"It might have been musk, but to me it smelled differently," he said. "Were you ever near a rattlesnake den in the west?"
Dr. Bird nodded.
"Then you know the peculiar reptilian odor which such a place gives off. Well, this smell was somewhat similar, although not the same by any manner of means. It was musky all right, but it was more snake than musk to me. I rather like musk, but this smell gave me the horrors."
"Did you hear any noises?"
"None at all. The men describe some rather peculiar noises and Sergeant Jervis is an old file and pretty apt to get things straight, but they may have been made by the men who were in trouble. I saw a man caught by a boa in South America once, and the noises he made might very well have been described in almost the same words as Jervis used."
"Thanks, Lieutenant," replied the Doctor. "I'll remember what you have told me. Now I think that we'll go into the cave."
"My orders are to allow no one to enter, Doctor."
"I beg your pardon. Carnes, where is that letter from the Secretary of War?"
Carnes produced the document. The lieutenant examined it and excused himself. He returned in a few moments with the commanding officer.
"In the face of that letter, Dr. Bird," said the major, "I have no alternative to allowing you to enter the cave, but I will warn you that it is at your own peril. I'll give you an escort, if you wish."
"If Lieutenant Pearce will come with me as a guide, that will be all that I need."
The lieutenant paled slightly, but threw back his shoulders.
"Do you wish to start at once, sir?" he asked.
"In a few moments. What is the floor of the cave like where we are going?"
"Quite wet and slimy, sir."
"Very slippery?"
"Yes, sir."
"In that case before we go in we want to put on baseball shoes with cleats on them, so that we can run if we have to. Can you get us anything like that?"
"In a few moments, sir."
"Good! As soon as we can get them we'll start. In the meantime, may I look at that gun that was found?"
The Browning machine-gun was laid before the doctor. He looked it over critically and sniffed delicately at it. He took from his pocket a phial of liquid, moistened a portion of the water-jacket of the weapon, and then rubbed the moistened part briskly with his hand. He sniffed again. He looked disappointed, and again examined the gun closely.
"Carnes," he said at length, "do you see anything on this gun that looks like tooth marks?"
"Nothing, Doctor."
"Neither do I. There are some marks here which might quite conceivably be finger-prints of a forty-foot giant, and those two parallel grooves look like the result of severe squeezing, but there are no tooth marks. Strange. There is no persistent odor on the gun, which is also strange. Well, there's no use in theorizing: we are confronted by a condition and not a theory, as someone once said. Let's put on those baseball shoes and see what we can find out."
Dr. Bird led the way into the cave, Carnes and the lieutenant following closely with electric torches. In each hand Dr. Bird carried a phosphorus hand-grenade. No other weapons were visible, although the doctor knew that Carnes carried a caliber .45 automatic pistol strapped under his left armpit. As they passed into the cave the lieutenant stepped forward to lead the way.
"I'm going first," said the doctor. "Follow me and indicate the turns by pressure on my shoulder. Don't speak after we have started, and be ready for instant flight. Let's go."
Forward into the interior of the cave they made their way. The iron cleats of the baseball shoes rang on the floor and the noise echoed back and forth between the walls, dying out in little eerie whispers of sound that made Carnes' hair rise. Ever forward they pressed, the lieutenant guiding the doctor by silent pressure on his shoulder and Carnes following closely. For half a mile they went on until a restrainable pressure brought the doctor to a halt. The lieutenant pointed silently toward a crack in the wall before them. Carnes started forward to examine it, but a warning gesture from the doctor stopped him.
Slowly, an inch at a time, the doctor crept forward, hand-grenades in readiness. Presently he reached the crack and, shifting one of the grenades into his pocket, he drew forth an electric torch and sent a beam of light through the crack into the dark interior of the earth.
For a moment he stood thus, and then suddenly snapped off his torch and straightened up in an attitude of listening. The straining ears of Carnes and Lieutenant Pearce could hear a faint slithering noise coming toward them, not from the direction of the crack, but from the interior of the cave. Simultaneously a faint, musky, reptilian odor became apparent.
"Run!" shouted the doctor. "Run like hell! It's loose in the cave!"
The lieutenant turned and fled at top speed toward the distant entrance to the cave, Carnes at his heels. Dr. Bird paused for an instant, straining his ears, and then threw a grenade. A blinding flash came from the point where the missile struck and a white cloud rose in the air. The doctor turned and fled after his companions. Not for nothing had Dr. Bird been an athlete of note in his college days. Despite the best efforts of his companions, who were literally running for their lives, he soon caught up with them. As he did so a weird, blood-curdling screech rose from the darkness behind them. Higher and higher in pitch the note rose until it ended suddenly in a gurgling grunt, as though the breath which uttered it had been suddenly cut off. The slithering, rustling noise became louder on their trail.
"Faster!" gasped the doctor, as he put his hand on Carnes' shoulder and pushed him forward.
The noise of pursuit gained slightly on them, and a sound as of intense breathing became audible. Dr. Bird paused and turned and faced the oncoming horror. His electric torch revealed nothing, but he listened for a moment, and then threw his second grenade. Keenly he watched its flight. It flew through the air for thirty yards and then struck an invisible obstruction and bounded toward the ground. Before it struck the downward motion ceased, and it rose in the air. As it rose it burst with a sharp report, and a wild scream of pain filled the cavern with a deafening roar. The doctor fled again after his companions.
By the time he overtook them the entrance of the cave loomed before them. With sobs of relief they burst out into the open. The guards sprang forward with raised rifles, but Dr. Bird waved them back.
"There's nothing after us, men," he panted. "We got chased a little way, but I tossed our pursuer a handful of phosphorus and it must have burned his fingers a little, judging from the racket he made. At any rate, it stopped the pursuit."
The major hurried up.
"Did you see it, Doctor?" he asked.
"No, I didn't. No one has ever seen it or anything like it. I heard it and, from its voice, I think it has a bad cold. At least, it sounded hoarse, so I gave it a little white phosphorus to make a poultice for its throat, but I didn't get a glimpse of it."
"For God's sake, Doctor, what is it?"
"I can't tell you yet, Major. So far I can tell, it is something new to science and I am not sure just what it looks like. However, I hope to be able to show it to you shortly. Is there a telegraph office here?"
"No, but we have a Signal Corps detachment with us, and they have a portable radio set which will put us in touch with the army net."
"Good! Can you place a tent at my disposal?"
"Certainly, Doctor."
"All right, I'll go there, and I would appreciate it if you would send the radio operator to me. I want to send a message to the Bureau of Standards to forward me some apparatus which I need."
"I'll attend to it, Doctor. Have you any special advice to give me about the guarding?"
"Yes. Have you, or can you get, any live stock?"
"Live stock?"
"Yes. Cattle preferred, although hogs or sheep will do at a pinch. Sheep will do quite well."
"I'll see what I can do, Doctor."
"Get them by all means, if it is possible to do so. Don't worry about paying for them: secret service funds are not subject to the same audit that army funds get. If you can locate them, drive a couple of cattle or half a dozen sheep well into the cave and tether them there. If you don't get them, have your sentries posted well away from the cave mouth, and if any disturbance occurs during the night, tell them to break and run. I hope it won't come out, but I can't tell."
A herd of cattle was soon located and two of the beasts driven into the cave. Two hours later a series of horrible screams and bellowings were heard in the cave. Following their orders the sentries abandoned their posts and scattered, but the noise came no nearer the mouth, and in a few minutes silence again reigned.
"I hope that will be all that will be needed for a couple of days," said the doctor to the commanding officer, "but you had better have a couple more cattle driven in in the morning. We want to keep the brute well fed. Is there a tank stationed at Fort Thomas?"
"No, there isn't."
"Then radio Washington that I want the fastest three-man tank that the army has sent here at once. Don't bother with military channels, radio direct to the Adjutant General, quoting the Secretary of the Treasury as authority. Tell him that it's a rush matter, and sign the message 'Bird' if you are afraid of getting your tail twisted."
Twice more before the apparatus which the doctor had ordered from Washington arrived cattle were driven into the depths of the cave, and twice were the screams and bellowings from the cave repeated. Each time searching parties found the cattle gone in the morning. A week after the doctor's arrival, a special train came up, carrying four mechanics from the Bureau of Standards, together with a dozen huge packing cases. Under the direction of the doctor the cases were unpacked and the apparatus put together. Before the assembly had been completed the tank which had been requested arrived from Camp Meade, and the Bureau mechanics began to install some of the assembled units in it.
The first apparatus which was installed in the tank consisted of an electric generator of peculiar design which was geared to the tank motor. The electromotive force thus generated was led across a spark gap with points of a metallic substance. The light produced was concentrated by a series of parabolic reflectors, directed against a large quartz prism, and thence through a lens which was designed to throw a slightly divergent beam.
"This apparatus," Dr. Bird explained to the Signal Corps officer, who was an interested observer, "is one which was designed at the Bureau for the large scale production of ultra-violet light. There is nothing special about the generator except that it is highly efficient and gives an almost constant electromotive force. The current thus produced is led across these points, which are composed of magnalloy, a development of the Bureau. We found on investigation that a spark gave out a light which was peculiarly rich in ultra-violet rays when it was passed between magnesium points. However, such points could not be used for the handling of a steady current because of lack of durability and ease of fusion, so a mixture of graphite, alundum and metallic magnesium was pressed together with a binder which will stand the heat. Thus we get the triple advantages of ultra-violet light production, durability, and high resistance.
"The system of reflectors catches all of the light thus produced except the relatively small portion which goes initially in the right direction, and directs it on this quartz prism where, due to the refractive powers of the prism, the light is broken up into its component parts. The infra-red rays and that portion of the spectrum which lies in the visible range, that is, from red to violet inclusive, are absorbed by a black body, leaving only the ultra-violet portion free to send a beam through this quartz lens."
"I thought that a lens would absorb ultra-violet light," objected the signal officer.
"A lens made of glass will, but this lens is made of rock crystal, which is readily permeable to ultra-violet. The net result of this apparatus is that we can direct before us as we move in the tank a beam of light which is composed solely of the ultra-violet portion of the spectrum."
"In other words, an invisible light?"
"Yes. That is, invisible to the human eye. The effect of this beam of ultra-violet light in the form of severe sunburn would be readily apparent if you exposed your skin to it for any length of time, and the effects on your eyesight of continued gazing would be apt to be disastrous. It would produce a severe opthalmia and temporary impairment of the vision, somewhat the same symptoms as are observed in snow blindness."
"I see. May I ask what is the object of the whole thing?"
"Surely. Before we can successfully combat this peculiar visitant from another world, it is necessary that we gain some idea of the size and appearance of it. Nothing of the sort has before made its appearance, so far as the annals of science go, and so I am forced to make some rather wild guesses at the nature of the animal. You are probably aware of the fact that the property of penetration possessed by all waves is a function of their frequency, or, perhaps I should say, of their wave-length?"
"Certainly."
"The longer rays of visible light will not penetrate as deeply into a given substance as the shorter ultra-violet rays. This visitor is evidently from some unexplored and, indeed, unknown cavern in the depths of the earth where visible light has never penetrated. Apparently in this cavern the color of the inhabitants is ultra-violet, and hence invisible to us."
"You are beyond my depth, Doctor."
"Pardon me. You understand, of course, what color is? When sunlight, which is a mixture of all colors from infra-red to ultra-violet inclusive, falls on an object, certain rays are reflected and certain others are absorbed. If the red rays are reflected and all others absorbed, the object appears red to our eyes. If all the rays are reflected, the object appears white, and if all are absorbed, it appears black."
"I understand that."
"The human eye cannot detect ultra-violet. Suppose then, that we have an object, either animate or inanimate, the surface of which reflects only ultra-violet light, what will be the result? The object will be invisible."
"I should think it would be black if all the rays except the ultra-violet were absorbed."
"It would, but mark, I did not say the others were absorbed. Are you familiar with fluorescein?"
"No."
"I think you are. It is the dye used in making changeable silk. If we fill a glass container with a fluorescein solution and look at it by reflected light it appears green. If we look at it by transmitted light, that is, light which has traversed the solution, it appears red. In other words, this is a substance which reflects green light, allows a free passage to red light, and absorbs all other light. This creature we are after, if my theory is correct, is composed of a substance which allows free passage to all of the visible light rays and at the same time reflects ultra-violet light. Do I make this clear?"
"Perfectly."
"Very well, then. My apparatus will project forward a beam of ultra-violet light which will be in much greater concentration than exists in an incandescent electric light. It is my hope that this light will be reflected by the body of the creature to a sufficient to allow me to make a photograph of it."
"But won't your lens prevent the ultra-violet light from reaching your plate?"
"An ordinary lens made of optical glass would do so, but I have a camera here equipped with a rock crystal lens, which will allow ultra-violet light to pass through it practically unhindered, and with very slight distortion. When I add that I will have my camera charged with X-ray film, a film which is peculiarly sensitive to the shorter wave-lengths, you will see that I will have a fair chance of success."
"It sounds logical. Would you allow me to accompany you when you make your attempt?"
"I will be glad of your company, if you can drive a tank. I want to take Carnes with me, and the tank will only hold two besides the driver."
"I can drive a tractor."
"In that case you should master the tricks of tank driving in short order. Get familiar with it and we'll appoint you as driver. We'll be ready to go in to-night, but I am going to wait a day. Our friend was fed last night, and there is less chance he'll be about."
The early part of the next evening was marked by howls and screams coming from the mouth of the cave. As the night wore on the noises were quite evidently coming nearer and the sentries watched the cave mouth nervously, ready to bolt and scatter according to their orders at the first alarm. About two A. M. the doctor and Carnes climbed into the tank beside Lieutenant Leffingwell, and the machine moved slowly into the cave. A search-light on the front of the tank lighted the way for them and, attached to a frame which held it some distance ahead of them, was a luckless sheep.
"Keep your eye on the mutton, Carnes," cautioned the doctor. "As soon as anything happens to it, shut off the search-light and let me try to get a picture. As soon as I have made my exposures I'll tell you, and you can snap it on again. Lieutenant, when the picture is made, turn your tank and make for the entrance to the cave. If we are lucky, we'll get out."
Forward the tank crawled, the sheep bleating and trying to break loose from the bonds which held it. It was impossible to hear much over the roar of the motor, but presently Dr. Bird leaned forward, his eyes shining.
"I smell musk," he announced. "Get ready for action."
Even as he spoke the sheep was suddenly lifted into the air. It gave a final bleat of terror, and then its head was torn from its body.
"Quick, Carnes!" shouted the doctor.
The search-light went out, and Carnes and the lieutenant could hear the slide of the ultra-violet light which Dr. Bird was manipulating open. For two or three minutes the doctor worked with his apparatus.
"All right!" he cried suddenly. "Lights on and get out of here!"
Carnes snapped on the search-light and Lieutenant Leffingwell swung the tank around and headed for the cave mouth. For a few feet their progress was unhindered and then the tank ceased its forward motion, although the motor still roared and the track slid on the cave floor. Carnes watched with horror as one side of the tank bent slowly in toward him. There was a rending sound, and a portion of the heavy steel fabric was torn away. Dr. Bird bent over something on the floor of the tank. Presently he straightened up and threw a small object into the darkness. There was a flash of light, and bits of flaming phosphorus flew in every direction. The anchor which held the tank was suddenly loosed and the machine crawled forward at full speed, while a roar as of escaping air mingled with a bellowing shriek burdened the smoke-laden air.
"Faster!" cried the doctor, as he threw another grenade.
Lieutenant Leffingwell got the last bit of speed possible out of the tank and they reached the cave mouth without further molestation.
"I had an idea that our friend wouldn't care to pass through a phosphorus screen," said Dr. Bird with a chuckle as he climbed out of the tank. "He must have been rather severely burned the other day, and once burned is usually twice shy. Where is Major Brown?"
The commanding officer stepped forward.
"Drive a couple of cattle into the cave, Major," directed Dr. Bird. "I want to fill that brute up and keep him quiet for a while. I'm going to develop my films."
Lieutenant Leffingwell and Carnes peered over the doctor's shoulders as he manipulated his films in a developing bath. Gradually vague lines and blotches made their appearance on one of the films, but the form was indistinct. Dr. Bird dropped the films in a fixing tank and straightened up.
"We have something, gentlemen," he announced, "but I can't tell yet how clear it is. It will take those films fifteen minutes to fix, and then we'll know."
In a quarter of an hour he lifted the first film from the tank and held it to the light. The film showed a blank. With an exclamation of disappointment he lifted a second and third film from the tank, with the same result He raised the fourth one.
"Good Lord!" gasped Carnes.
In the plate could be plainly seen the hind quarters of the sheep held in the grasp of such a monster as even the drug-laden brain of an opium smoker never pictured. Judging from the sheep, the monster stood about twenty feet tall, and its frame was surmounted by a head resembling an overgrown frog. Enormous jaws were opened to seize the sheep but, to the amazement of the three observers, the jaws were entirely toothless. Where teeth were to be expected, long parallel ridges of what looked like bare bone, appeared, without even a rudimentary segregation into teeth. The body of the monster was long and snakelike, and was borne on long, heavy legs ending in feet with three long toes, armed with vicious claws. The crowning horror of the creature was its forelegs. There were of enormous length, thin and attenuated looking, and ended in huge misshapen hands, knobby and blotched, which grasped the sheep in the same manner as human hands. The eyes were as large as dinner plates, and they were glaring at the camera with an expression of fiendish malevolence which made Carnes shudder.
"How does that huge thing ever get through that crack we examined?" demanded the lieutenant.
Dr. Bird rubbed his head thoughtfully.
"It's not an amphibian," he muttered, "as is plainly shown by the shape of the limbs and the lack of a tail, and yet it appears to have scales of the true fish type. It corresponds to no recovered fossil, and I am inclined to believe it is unique. The nervous organisation must be very low, judging from the lack of forehead and the general conformation. It has enormous strength, and yet the arms look feeble."
"It can't get through that crack," insisted the lieutenant.
"Apparently not," replied the doctor. "Wait a moment, though. Look at this!"
He pointed to the great disproportion between the length and diameter of the forelegs, and then to the hind legs.
"Either this is grave distortion or there is something mighty queer about that conformation. No animal could be constructed like that."
He turned the film so that an oblique light fell on it. As he did so he gave a cry of astonishment.
"Look here!" he said sharply. "It does get through that crack! Look at those arms and hands! There is the answer. This creature is tall and broad, but from front to rear it can measure only a few inches. The same must be true of the froglike head. That animal has been developed to live and move in a low roofed cavern, and to pass through openings only a few inches wide. Its bulk is all in two dimensions!"
"I believe you're right," said Carnes as he studied the film.
"There is no doubt of it," answered the doctor. "Look at those paws, too, Carnes. That substance isn't bone, it's gum. The thing is so young and helpless that it hasn't cut its teeth yet. It must be a baby, and that is the reason why it made its way into the cave when no other of its kind ever has."
"How large are full grown ones if this is a baby?" asked the lieutenant.
"The Lord alone knows," replied Dr. Bird. "I hope that I never have to face one and find out. Well, now that we know what we are fighting, we ought to be able to settle its hash."
"High explosive?" suggested the lieutenant.
"I don't think so. With such a low nervous organization, we would have to tear it practically to pieces to kill it, and I am anxious to keep it from mutilation for scientific study. I have an idea, but I'll have to study a while before I am sure of the details. Send me the radio operator."
The next day the Bureau mechanics began to dismount the apparatus from the tank and to assemble another elaborate contrivance. Before they had made an end of the work additional equipment arrived from Washington, which was incorporated in the new set-up. At length Dr. Bird pronounced himself ready for the attempt.
Under his direction, three cattle were driven into the cave and there tethered. They were there the next morning unharmed, but the second night the now familiar bellowing and howling came from the depths of the cave and in the morning two of the cattle were gone.
"That will keep him quiet for a day or two," said the doctor, "and now to work!"
The tank made its way into the cave, dragging after it two huge cables which led to an engine-driven generator outside the cave. These cables were attached to the terminals of a large motor which was set up in the cave near the place where the cattle were customarily tethered. This motor was the actuating force which turned two generators, one large and one small. The smaller one was mounted on a platform on wheels, which also contained the spark gaps, the reflectors and other apparatus which produced the beam of ultra-violet light which had been used to photograph the monster.
From the larger generator led two copper bars. One of these was connected to a huge copper plate which was laid flat on the floor of the cave. The other led to a platform which was erected on huge porcelain insulators some fifteen feet above the floor. Huge condensers were set up on this platform, and Dr. Bird announced himself in readiness.
A steer was dragged into the cave and up a temporary runway which led to the platform containing the condensers, and there tied with the copper bus bar from the larger generator fastened to three flexible copper straps which led around the animal's body. When this had been completed, everyone except the doctor, Carnes, and Lieutenant Leffingwell left the cave. These three crouched behind the search-light which sent a mild beam of ultra-violet onto the platform where the steer was held. The engine outside the cave was started, and the three men waited with tense nerves.
For several hours nothing happened. The steer tried from time to time to move and, finding it impossible, set up plaintive bellows for liberty.
"I wish something would happen," muttered the lieutenant. "This is getting on my nerves.
"Something is about to happen," replied Dr. Bird grimly. "Listen to that steer."
The bellowing of the steer had suddenly increased in volume and, added to the note of discontent, was a note of fright which had previously been absent. Dr. Bird bent over his ultra-violet search-light and made some adjustments. He handed a helmetlike arrangement to each of his companions and slipped one on over his head.