Chapter VI: Part 6

Terrified by this picture of what had happened, Mrs. Quayle involuntarily clutched the jewels encircling her neck as if to protect them from some invisible brigand. The schoolmaster, also, seemed to suffer additional discomfort. Miranda's way of putting it, however, failed to satisfy the others. Leighton stoutly refused to believe in magic. Herran, in voluble Spanish, insisted that magic alone could explain the affair. Miranda repeated his alligator theory.

"This cave is alive," he added. "You see the mark of the feets?"

"Where is Mr. Arthur?" suddenly asked Una.

They had been so absorbed in the mystery of the vanishing tunnel that the absence of one of their number had not been noticed. Una's startled query brought them face to face with another puzzle, as baffling and uncanny, in a way, as the wall of rock that had come from nowhere and planted itself between them and the entrance to the cave. Raoul had disappeared; search as they might, call as loudly as they could, no trace of him was to be found. Had he deliberately deserted them, or had he suddenly been spirited away by the same invisible agency that had prevented their leaving the cave? The more credulous of the party believed he had been spirited away.

"But it is impossible," insisted Miranda angrily. "I see him now--and now he is not here. The canaille!"

"There is only one thing to be done," declared Leighton emphatically. "We can't get out of here; we must go on."

"Yes! Yes!" exclaimed Una.

"Caramba! What for we go on?" remonstrated Miranda. "We are lost, we starve, if we leave this place."

"You mean, we are lost if we stay here," reasoned Leighton. "There is nothing to be gained by staring at this rock. The fact that Arthur has disappeared, that the entrance to the tunnel has been closed, that there are fresh footprints besides our own all about us, proves that this cave is inhabited. Whoever they are, we must find these people."

Leighton's way of putting things was effective. It at least prevented a panic. Even Miranda admitted the necessity of the course proposed by the savant, and as Herran had nothing else to offer in its place, it was decided to press on with the exploration of the cave without delay.

Fortunately, they had a fair amount of provisions and enough oil to keep their lamps going for several days. Before starting on their expedition--when it promised to be nothing more than a "picnic"--this supply of food and fuel seemed far beyond any possible need. Now, thanks to the fussiness of Mrs. Quayle, who had insisted on these abundant preparations, there was no immediate danger of starvation. Each carried his or her portion of food in a light, capacious sack. These sacks, woven by the natives from vegetable fiber, swung easily from the shoulders. The oil for the lamps was in two cans, one of which Andrew carried, Raoul the other. Whatever had become of Raoul, his can of oil had not disappeared with him. It was found near the spot in the large cave where Miranda had turned back to take Mrs. Quayle to the tunnel. Here, then, Raoul had left them. Hoping for a clew, they examined the ground for his footprints, but could discover nothing. The path beyond showed the impress of sandaled feet only--and Raoul, they agreed, did not wear sandals. Either he had left the path and chosen the rocky floor of the cavern in its stead--in which case it would be impossible to discover his trail--or he had followed them to the tunnel and gone off on one of the side tracks that they had noticed and partially explored there. Why he should have done either of these things was quite beyond them to answer. At any rate, they tried every means to find him, and their failure left them more despondent than ever. All except Leighton and Una.

Failure did not daunt Leighton. He was convinced that by persevering in their exploration they would solve the mystery of the cave, gain tidings of David, and run down Raoul. Una shared his optimistic view, and both chafed at the reluctance of their companions to go ahead with the energy their plight demanded. The fact is, the feeling that they were caught in a cavern of unknown extent, connected with certain mysterious happenings in the immediate past, mixed up in the legendary history of a vanished race, and inhabited even now by strange beings in outlandish costumes, had a blighting effect upon them. Mrs. Quayle refused to be comforted and, as it was out of the question to go on without her, Leighton, like an astute general, proposed having lunch before doing anything else. Every one brightened up at the idea; it was one of those masterstrokes of policy that, when all else fails, saves the day. Miranda declared emphatically that food was "good for the estomach," and, as no one thought otherwise, they fell to with an appetite sharpened by their exertions and made fairly razor-like--although this they did not realize--by the bracing atmosphere of the cave.

There were bollos of corn and yucca--yellow, white, brown--variously flavored, soggy, solid. This was a concentrated food that just hit the need of a party of marooned picknickers. And there were large flat disks of cassava, a native bread that Mrs. Quayle declared, with some reason, resembled chips of wood, more than anything else, in taste and toughness. This, too, furnished the maximum of nourishment in a small space. These foods, with such fruits as the almond-like sapoti, the juicy nispera, the delicate chirimoyo, furnished a meal that aroused Miranda's enthusiasm, although to the untrained New England palate it was not quite so satisfying as it might be. The thought, too, that after this supply of food was exhausted, there would be nothing to eat, and no way of getting anything to eat, spoiled just that part of the picnic that should be most enjoyable. And then, worse than all, unthought of until now, there was the appalling problem of--water. In the lunch bags of Doctor Miranda and General Herran there were two small bottles of red wine; but when this was offered to Mrs. Quayle that unhappy lady's thirst for water reached an acute stage. She declared that all wine was poison, and that she would die if she couldn't get a drink of water. Even Leighton was disturbed. Water they must have, but--did it exist in a cave that was, apparently, caused by fire and not--as all respectable caves are--by water?

"Guatavita!" exclaimed Miranda, smacking his lips after a deep draught of claret.

"Guatavita!" echoed Leighton irritably. "Why not say the river Magdalena? How are we to reach Guatavita?"

"It is near," was the complacent reply. "It come into the cave."

"How do you know that?"

"Always there is water in the cave. And here--there is the lake outside."

"Yes, outside," said Leighton bitterly.

"But first it is inside."

Miranda's confident assertion was worth considering. That there might be--that there probably was--some subterranean connection between the cave and the lake--even if the former did come from fire--was a plausible theory. As he went over the matter in his own mind, Leighton's respect for Miranda's common sense jumped from zero to a comparatively high figure. But he was not convinced.

"You forget; we are above the level of the lake," he argued.

"That is true," agreed the doctor, who, in the meantime, bottle in hand, had been nervously walking about, peering into the darkness that surrounded them. "Yes, that is true. We come in over there; and always we walk up, up. The lake is always below. This path it never go down. But here--aha! Caramba!--is one other path--and it go down."

Miranda's voice shrilled with excitement. He was elated with the importance of his discovery. And it was important. The spot they had chosen for their lunch was the furthest point they had reached in their explorations, the point where Miranda had turned back to take Mrs. Quayle out of the cave and where they had last seen Raoul Arthur. It was marked by a huge pyramidal rock rising from the floor of the cave. Along one side of this rock the path they had followed went on indefinitely, in a gradual upward incline. It was to the other side that Miranda eagerly called attention. Placing his bottle of claret down on the rock beside him, he got on his knees and, with his nose almost touching the ground, made a minute study of the floor of the cave.

Even Andrew felt the contagion of the doctor's excitement. Fruits, bollos, cassavas were abandoned pell mell as one and all scrambled to their feet eager to find out what new puzzle Miranda had managed to pick up. The light from their lamps cast huge, uncertain shadows on the irregular masses of rock that everywhere blocked the view. At first there was nothing to be seen that differed essentially from what they had grown accustomed to in this subterranean world. There was the same chaos of jagged pinnacles and bowlders, the same display of irresistible energy that had been let loose and played itself out here ages ago. But in the midst of it all, zigzagging through this maze of dusty forms, there was the new path announced by Miranda. It led away from the central rock, or pillar, where they had taken their lunch, and formed an acute angle with the path they had already traversed. It was not so plainly marked as the latter, and appeared little more than a rift among the rocks that strewed the floor of the cave. But it was a path, there was no mistaking that. Among the evidences that it had been recently used was one that particularly delighted Miranda and justified his prolonged microscopic examination of the path itself--the footprints of a man wearing, not sandals, but shoes.

"Raoul Arthur!" exclaimed Leighton.

"Perhaps," agreed Miranda.

"Where could he have gone?" asked Una. "This path runs in nearly the same direction as the one we followed."

"We will see."

As a matter of fact, the two paths, starting together at the central rock and going thence in the same general direction, gradually diverged from each other, much as do the two lines that form the letter V. Then, another difference was noticeable. The first path followed a comparatively uniform level; the second dipped steadily downward. This peculiarity, first noted by Miranda, appealed particularly to Herran. Gloom had been the dominant mood with the general ever since he had entered the cave. He had made mental notes of things as they had happened, but he had not shared in the discussions of the others. This was partly due to his ignorance of English, partly to a sense of responsibility that he felt as a citizen of Bogota whose duty it was to guide a party of foreigners safely through one of the difficult regions of his native land. But now, at last, he had something to say, something that was due from him as their leader. Tugging at his beard in characteristic fashion, he gave the result of his observations in terse Spanish.

"At first we go away from the lake. Then we come back to it, just a little. Then we go away. Now this path take us right there again."

"That is it," agreed Miranda.

It sounded rather mixed up, and no one paid much attention to it. But at least it put General Herran in a better humor.

"Perhaps this will take us out of the cave," suggested Andrew. "The path is nearly in the right direction."

"I hope it means water, anyway," said Una, thinking of Mrs. Quayle.

They gathered up what was left of their provisions and set off again, single file, down the new path, General Herran in the lead, Andrew bringing up the rear. They had not gone many yards before they noticed the marked difference in the two paths. At first the change in level was scarcely perceptible; but now the descent became more and more abrupt, and as there was less sand and gravel for a foothold, they found the smooth surface of the rocks, tilted often at a sharp angle, anything but easy going. Another peculiarity that soon caught their attention was the lessening height of the cave's roof. Until now this roof had been so far above them that they had to throw their heads way back to see it, and even then it appeared in only vague outlines. Now it took a downward curve that brought it nearer and nearer to them. Following the same descending sweep it was evident that floor and roof would shortly come together and the confines, at least of that portion of the cave, would be reached.

Along with this new architectural feature in the structure of the cave, there was a noticeable change in the character of the rock forming it. Walls and floor had, until now, been sharp and jagged in contour, dull, almost black, in color. But the unevenness of surface was disappearing. The rocks were smoother, as if worn and rounded by constant rubbing. Vivid colors gleamed from wall and column with a pristine freshness suggesting that this part of the cave belonged to a far more distant period than the great rock chamber in which they had stopped to take their luncheon. Finally, they were surrounded at every hand by those spear-like formations, thrust upwards from the floor or depending from the roof, that give to the interiors of most caves their fantastic appearance--the stalactites and stalagmites about whose origin in the workshop of Nature there can be no doubt.

This change had an invigorating effect upon the explorers. Passing from the unrelieved gloom of the first cavern into this fairy-built grotto, with its bright hues and pleasing shapes, they began to forget their fears and felt instead something like the real enjoyment that belongs to unexpected adventure. Everything in the way of glorious surprise seemed possible. For one thing, Miranda's confident prediction was apparently about to be realized, a probability that the doctor celebrated by alternate chuckles and grunts of satisfaction.

"If we don't find water, there is at least no doubt that water has once been here," declared Leighton. "These stalactites make that certain."

"You will see--you will see," persisted Miranda. "It is the Lake Guatavita."

"How can that be?" argued Leighton. "No opening of the lake into this cave has ever been discovered."

"You will see."

One might almost imagine that the intricacies of the cave were as familiar to the doctor as the formula for his celebrated pills. But his confident attitude was only one part genuine to three parts bravado. He enjoyed opposing a scientist showing such supreme self-possession as Leighton, and he delighted in startling statements of fact that merely bewildered his hearers. But he was by no means sure in his own mind of the truth, or even the probability of the theory he was advancing. General Herran, however, who had heard as far back as he could remember the strange tales of mystery regarding Lake Guatavita, and had often speculated with other Bogotanos on the disappearance beneath its waters of the fabulous wealth of the ancient Chibchas, was keenly alive to the possibilities lying before them now that they were on the very spot haunted by so many fascinating traditions of his race. Like most natives of Bogota the Spanish blood in his veins was mixed with the blood of the Chibchas--and it was an infusion he was proud to own. Hence, he readily believed that at any moment they would stumble upon a perfect mountain of treasure, all the lost gold and emeralds that Spanish romancers had dreamed about and travelers of the old heroic times had risked their lives for.

They had now reached the end of the precipitous incline down which the path had led them, thankful to exchange the slipping and sliding, to which the tilted rocks had treated them, for the firm footing offered by a comparatively level floor. Here the roof hung only a few feet above their heads, whence it curved downward, glistening with the delicate fretwork that the subterranean torrents of bygone ages had carved upon it, until it became a part of the rock-strewn ground beneath. The chamber thus formed became a long, spacious corridor, one side of which was open to the vast amphitheater they had just left, the other side stoutly hemmed in by a maze of stalactites and stalagmites looming up as sentinels in front of a wall that could be dimly seen behind them. Down the middle of this corridor lay the path they had been following, wider now and showing the imprint of many sandaled feet. Before them, at the end of the corridor, they could distinguish the outlines of another wall, apparently marking the limit of this portion of the cave.

"There is your lake," said Leighton ironically to Miranda, who shrugged his shoulders in reply.

"At any rate, Uncle Harold," said Una reproachfully, "there must be an opening here. And the air is just heavenly! Instead of walking, one could dance."

The others appeared to feel the truth of Una's observation, for they moved along with a briskness, a snap, they had not shown before. This was particularly noticeable in Mrs. Quayle, who seemed to be propelled by some inner gayety of spirit that quite changed her usually sedate manner and appearance. The transformation was not lost on Una, who was both amused and puzzled by it.

"Look at Mrs. Quayle's jewelry!" she exclaimed. "It is dancing about as if it were moved by a breeze from somewhere."

"What do you mean? I can't feel any breeze," declared Leighton. "The singular fluttering of Mrs. Quayle's jewelry simply means, I suppose, that the wearer is, as usual, agitated."

That Mrs. Quayle was agitated, and not in the joyous frame of mind that Una at first supposed, began to be painfully evident. Ever since she had come into the cave agitation had been a chronic condition with her. But in this instance it hardly explained the eccentric activity that had suddenly developed among the ancient heirlooms that she guarded so jealously. The large gold pendants that dangled from her necklace beat an unaccountable tattoo upon her neck and shoulders, while the massive brooch fastened to her bodice showed an obstinate tendency to break away from its moorings. Even the gold rings on her fingers seemed possessed with a rebellious spirit, a mischievous desire to dance in unison with brooch and necklace, while two heavy bracelets, made of links and chains, clicked and snapped like castanets under the prevailing terpsichorean influence.

For several minutes before Una drew attention to these strange antics Mrs. Quayle had been unhappily aware of the insurrection that had broken out among her treasures and had clutched frantically at them in an unavailing attempt to quiet their ill-timed frenzy. She dabbed at them with one hand and caressed them with the other, only to find that as soon as they were freed from her restraining touch they flapped and jingled and tugged at her with renewed energy. Finally, with the eyes of all the party upon her, the terrified lady gave up in despair.

"I don't know what is the matter with them," she wailed; "they never acted this way before. I am not agitated," she added irritably, "as Mr. Leighton says. And I don't think it is a breeze either. It takes more than a breeze to make bracelets and brooches dance. They are just possessed, and for no reason at all. Oh, why did I wear these precious things on this terrible journey!"

Doctor Miranda, with the steadfast gaze of an exorcist, planting himself firmly in front of her, his arms crossed on his chest Bonaparte-fashion, added to Mrs. Quayle's dismay.

"I think she have the malaria," he announced solemnly. "I give her my pills----"

"I won't take your old pills," was the spirited reply. "They nearly did for poor Mr. Andrew. I think they may kill him yet. There is nothing the matter with me. I want to get out of this cave--and I'm going to this very minute."

Never in the annals of her long career as housekeeper and self-effacing lady's companion had Mrs. Quayle been known to give way to such open defiance of any one belonging to the opposite sex. And, as if to show that she meant every word she said, she brushed past the astonished doctor and strode ahead of the others along the path leading down the corridor. To no one was her behavior more astonishing than to Leighton, in whom the reserve of the scientist was sorely strained by this sudden show of daring from a creature whose timidity was proverbial. As leader of the expedition, and obeying also the skeptical bent of his nature, the savant felt that his own dignity was involved.

"Mrs. Quayle is perfectly right," he announced coolly; "we must lose no more time in these trifles. What if her jewelry does show a disposition to dance? A woman's jewelry is always ridiculous--and Mrs. Quayle's has always been a puzzle besides."

But the rest of the party soon found that Mrs. Quayle was not an easy leader to follow. Where before she kept them back by her ineffectual efforts to get over the various obstacles encountered in their explorations, and had needed their help at almost every step, she now set them a pace that atoned for her former lagging. Whether this amazing activity was due to a sudden attack of fever, as Doctor Miranda maintained, or whether it came from a frantic desire to escape from a region that filled her with superstitious terrors, Mrs. Quayle showed no sign of giving up what she proposed to do, whatever that might be. On the contrary, as the far end of the corridor grew more distinct she sped along faster than ever. Her rebellious jewelry fluttered and twitched and danced more vigorously, until it fairly stood out before her, straining and pulling her along, breathless and hysterical, as if drawn by some irresistible force.

"I can't stop it! I can't stop it!" she gasped.

To which Miranda, puffing along in her wake, replied with dramatic emphasis: "This little woman must be stop!"

But this was not easy, even for a doctor with unlimited experience in quinine. The smooth, tapering surfaces of the stalactites, standing on guard in long rows down one side of the corridor, glinted derisively as the explorers rushed past them frantically trying to curb the frenzy that had seized this perfectly harmless woman who was now leading them on to a goal that might have all kinds of disaster in store for them. As they drew nearer the end of the corridor, the expected opening that was to deliver them from their subterranean prison was not visible, at least to the hasty glance that could be spared from the absorbing pursuit of Mrs. Quayle. Nevertheless, the awkward rapidity with which they were hurrying on to their fate was to be rewarded, apparently, by the discovery of something that was different, at any rate, from the wilderness of rocks that hitherto had baffled them in this gloomy underworld--and it was not General Herran's mountain of gold and emeralds, either.

Something made by man, and not by nature, was here. This was unmistakably revealed in an odd sort of structure towards which they were hurrying. At last they were confronted, they believed, by the clew to the mysterious beings who inhabited the place, whose presence had been indicated by the footprints, by the man in the toga, seen, or imagined, by Andrew, and vaguely suggested by the weird disappearance of the entrance to the tunnel through which they had hoped to make their escape. Here all these things that had filled them with alternate anxiety and curiosity were to be explained. Unfortunately, Mrs. Quayle's impatience to get on gave them no opportunity to reconnoitre, at a safe distance, the object they were approaching. Leighton especially, accustomed to the careful methods of science, would have preferred a more deliberate and cautious mode of travel to the brainless hurry into which his housekeeper had plunged them. As it was, the object looming before them, so far as they could snatch time to make it out, resembled a huge stone windlass. Even the cylindrical drum and the long curved handle hanging at the side of one of the tall uprights were of stone. Certainly, a windlass like this--if it was a windlass--had never been seen before. It could not be the work of modern times--it was much too clumsy for that. And of stone! Perhaps it belonged to the Stone Age. It was conceivable--and the notion stirred the depths of the savant's soul with delight--that here, in this subterranean chamber of the Andes, they were about to stumble upon an archæological find that would revolutionize the current theories as to primitive man and his development. But--was it a windlass? The two uprights carrying the long horizontal drum at the top, instead of in the middle, were some ten or fifteen feet high. With such an abnormal height, and such singular construction, the THING might be intended to serve as a gallows quite as reasonably as a windlass. Whoever would have believed that they had the gallows in the Stone Age! There, sure enough, was the rope dangling most suggestively from the crosspiece--or drum, whichever it might be. But then, a rope was the conventional adornment, whether for gallows or windlass. As they came within fifty yards of it, the THING looked unquestionably more and more like a gallows, less like a windlass. It stood within ten feet of the wall, through a long, wide aperture in which one end of the rope disappeared. The other end, attached to what appeared to be a great oblong stone, lay coiled upon the ground.

Not until she had almost reached it did Mrs. Quayle realize the oddity of the structure towards which she had been racing. Then its resemblance to a gallows suddenly flashed upon her. With a gurgle of horror she threw herself upon the ground, unable, apparently, so long as she remained upon her feet, to contend against the invisible influence that forced her to run fairly into the arms of this terrifying object. Prostrate between two rocks lying across the path, her wild flight came to an end. Here her companions gathered around her--Miranda, puffing and panting from his exertions, determined to allay the violent attack of fever that he still believed was the cause of the lady's unaccountable paroxysms; Leighton, torn between the psychological interest of the case and the archæological puzzle awaiting solution; Andrew, his huge hands waving about in helpless dismay, muttering incoherent advice to any one who would listen, and Una, anxious to soothe an agitation that, she conceived, was due merely to a case of nerves.

"She will be all right--soon she will be all right," declared Miranda, intent on his professional duties as he knelt on the ground beside Mrs. Quayle. With which comforting assurance he seized one of her hands, and with his other hand tried to force open her mouth.

"I am all right," she shrieked, tearing herself out of his clutches. "There's nothing the matter with me. Something is pulling me to that terrible thing over there. It seems to be my jewelry. My necklace is cutting my head off. This brooch!--oh! it's awful! What shall I do? What is the matter?"

"It is very simple," declared Leighton sternly. "Take off your jewelry if it bothers you. I don't see why you should be wearing it, anyway."

Mrs. Quayle clutched wildly at her necklace and brooch, loath to part with them and evidently regarding the people gathered around her as little better than a lot of brigands who had lured her here to rob her of her treasures. Every one else heartily agreed with Leighton's proposal.

"Caramba! That is true!" shouted Miranda delightedly. "This necklace, it choke her too much. I take him off of her."

Before Mrs. Quayle could protest further, Miranda seized her by the throat, hauling at the massive necklace in an effort to find the clasp that held it in place. The task proved difficult and promised to develop features that savored more of surgery than anything else. The trouble was not so much from the defensive tactics employed by Mrs. Quayle--who contrived to elude Miranda's grasp with surprising agility--as it was with the necklace itself. Never was a simple piece of jewelry more rebellious. It slipped through the doctor's fingers and jumped about and tugged at its victim's neck in the most baffling and erratic manner. But Miranda, growing more eager and determined, triumphed at last. Holding the snakelike coil in both hands as in an iron vise, he tore the chain apart with a masterly jerk.

And then an odd thing happened. Bounding to his feet, elated with his success, and holding the necklace towards his companions as if it were a hard-won trophy, Miranda suddenly spun around like a top, his arms shot straight out in front of him, and in this posture, before any one knew what he was about, he fairly raced towards the ominous apparatus at the end of the corridor and hurled himself on the oblong stone beneath it.

XIV

THE BLACK MAGNET

For once Doctor Miranda had nothing to say. To the eager queries of those about him he returned a grimace and a scowl of rage. Then he asked savagely for Mrs. Quayle.

"There is her neckalace," he said indignantly, letting go his hold on that extraordinary piece of jewelry and scrambling to his feet with as much dignity as was left to him.

"Will you tell me what all this means?" demanded Leighton sternly.

"How I know?" retorted Miranda, glaring venomously at him. "I pull the neckalace from the neck, and it fly from me. When I follow, it fly more fast--and it get stronger and it fly harder every time until it touch the rock. Then it stop and not come loose."

Sure enough, on the greenish-black rock over which they were bending, the necklace was spread out to its full length. With a quick jerk, Leighton dislodged one of the ends from its resting place. Letting it go, it returned to its original position with the sharp snap of a steel spring.

"A magnet! The most amazing magnet ever heard of!" exclaimed Leighton.

"A magnet that pull gold!" scoffed Miranda. "That is the foolishness!"

But Leighton was right. Each time the necklace was pulled away it was drawn back to the rock by a strong, invisible force. Repeated trials brought the same result. Leighton's curiosity was excited as it had never been before; but his most careful examination of the strange phenomenon failed to detect anything more than the fact that the substance exerting this unknown force was not stone but something more nearly akin to metal. It was neither so heavy nor so hard as iron. To the touch its surface faintly resembled the adhesive softness of velvet, although a blow from a stone, causing a clear, ringing sound, left not the slightest mark upon it. In the main, this block of metal--or whatever it might be called--was a deep black, tinged with a variegated shade of green that played over it according to the angle at which the ray from a light held above it was reflected. Dark lines of green followed the indentations traversing its surface. Cylindrical in shape, it weighed, according to Leighton's estimate, at least a ton. Imbedded in a deep groove around its center was a rope, measuring two inches in diameter, of pliable fiber, resembling the long lianas that festoon the trees of a tropical forest. This rope lay in a seamanlike coil on the ground, with the further end attached to the transverse beam of the scaffolding overhead.

"It is a magnet, nothing else," reiterated Leighton; "a magnet of a kind utterly unknown to science. All we can say is that this black metal has an affinity for gold--unless it turns out that Mrs. Quayle's jewelry is merely iron gilded over."

This doubt as to the genuineness of the housekeeper's treasures was promptly denied, however, by Una, who guaranteed their sterling quality.

"Let us test the rest of her jewelry," proposed Leighton.

To this further demand on her property Mrs. Quayle, wedged in between two rocks on the path where they had left her, too terrified to move, offered only a feeble protest. It mattered little to her, in her present condition, if her bracelets and brooch followed the necklace to their doom. One by one they were, accordingly, removed by Una, who, probably because she was less excitable than Miranda--and because, too, she had profited by his untoward experience in the same undertaking--was able to handle these pieces of jewelry without mishap. The force with which they were pulled towards the Black Magnet, however, and the tenacity with which they stuck to it, gave ample evidence that they answered to the same influence that still held the necklace.

"That is enough," said Leighton triumphantly. "The thing is proved. This is a gold magnet. If we lived in the Middle Ages we would call it the Philosopher's Stone. The theory that such a substance exists has attracted scientists who were more given to dreaming than practical observation. In this age we have neither looked for it nor believed in the possibility of its existence. And here it is!"

"What it make here?" demanded Miranda. "Tied by a rope to the machine--some one use it."

The inference, logical enough, certainly, increased Leighton's excitement. That the magnet was known and used by the inhabitants of the cave--if there were inhabitants--was evident. Under certain conditions a bar of metal that could attract gold with such force as that displayed by the Black Magnet would be of untold value. Here, where there were no evidences of mining operations, and attached to this primitive machine, it was difficult to explain what it was actually used for.

Leighton, more and more mystified, determined that the best way to solve the puzzle was to operate the machine in the manner indicated by its structure. It was not, as he pointed out--but as they in their first excitement imagined--a gallows. Instead, it was a winch, built in the most simple and archaic fashion; and as the Black Magnet was attached to it, the evident purpose was to hoist that huge body from the ground. Before testing this theory, Mrs. Quayle, who had recovered from her collapse sufficiently to join the others, insisted that her jewelry should be released from the magnet. Suspicious of the intentions of some of her companions, she was determined to regain possession of her treasures at once. But, as it was apparently impossible to wear her jewelry with comfort, or even safety, in the immediate vicinity of the Black Magnet, necklace, brooch and bracelets were removed to a distant corner of the corridor and there placed beneath a pile of stones. This done, the four men started to work the two long handles of the winch. At first these were turned with difficulty, the resistance proving, at least to Leighton's satisfaction, that the machine had not been used for a long time. Gradually, however, the coil of liana was transferred from the ground to the transverse beam overhead until it pulled taut with the magnet beneath.

Then came the real trial of strength. The magnet wouldn't budge. Miranda puffed and grumbled over the task, declaring it impossible. The rest stopped and rubbed their arms ruefully. But Leighton was inexorable. Encouraging the others, and keeping them at it, by dint of increased exertion--to which Una brought additional assistance--the great Black Magnet was finally dragged from its moorings and held suspended just above the ground. It formed a perfect cylinder, about four feet long by a foot and a half in diameter, and must have weighed, they estimated, considerably over a ton--ten tons, vowed Miranda. On a winch of modern design this weight would not have been difficult to lift. But the hoisting apparatus they were using lacked the ordinary adjustments for counterbalancing such weights; hence, the muscular force needed proved no small matter.

"It take twenty men to lift this magnet," growled Miranda.

"Twenty men could do it more easily than four men and a woman, undoubtedly," replied Leighton. "But four can do it."

And he was right. Inch by inch the magnet rose from the ground--for what ultimate purpose was not very clear, any more than that it was thought necessary by Leighton, in order to discover the use to which this strange bar of metal had been put, first to test the appliance obviously intended to bring it into action. It reached a height of one foot from the ground, then two, then three feet; then it stopped. There were groans and smothered imprecations, and it looked very much as if the huge bar of metal would come crashing down to the ground again. But the men, urged on by Leighton, did not give in. And then--there was a grating noise, as if some hidden mechanism in the scaffolding had been set free. After which a strange thing happened. The transverse beam at the top of the windlass detached itself from one of the uprights supporting it and, using the other upright as a fulcrum, slowly swung to the wall of the cave, where it rested in a socket, bringing the magnet that was suspended from it, directly over a shelf-like projection beneath.

"Keep on! Keep on!" cried Leighton encouragingly. "Now we will see."

Thoroughly aroused, the others redoubled their exertions. The magnet remained stationary for a few seconds, the liana supporting it tightening with every revolution of the drumhead at which the men were laboring. Then it slowly disappeared downward, the liana uncoiling itself, thus reversing the movement that before had carried it upward. There was a gradual increase in the momentum of its descent, followed by the splashing sound caused by the impact of a heavy body upon the surface of a pool of water; after which the liana was paid out until it reached its full length--when it suddenly slackened and came to a full stop.

"There, Mrs. Quayle, is your water," announced Leighton.

"Water!" sneeringly echoed a voice from the darkness behind them. "Say, rather, there is the secret of Guatavita!"

"Raoul Arthur!" exclaimed the others.

Letting go the handle of the windlass, they rushed to the spot where the Black Magnet had vanished. There, at one side of the rocky projection, stood Raoul, pale and haggard, the light in his lamp extinguished.

"I suspected this," he said, as if his sudden reappearance among them were the most natural thing in the world. "I knew from the direction of the path that it led back to the lake. I have been trying to reach this place for years. Oh, yes! I had heard something about it before--I don't deny that. But, of course, I expected to stay by you. So, when you started to leave the cave I came back, expecting to rejoin you. As I was examining the machine I was attacked by two men, thrown to the ground and left unconscious. I came to myself a few minutes ago--in time to congratulate you, it seems, upon solving the mystery of the cave."

"That is strange," said Leighton coldly. "You left us, without a word, at a time when you were needed. The attack that you say was made upon you we should have heard. But--we have heard nothing."

"Believe me, or not, as you like; it is true," was the sullen reply.

"Why do you say we have the secret of Guatavita?"

"Look!"

Raoul pointed to the projection in the wall behind which the Black Magnet had disappeared. It was not a shelf, as they had at first supposed, but the opening of a shaft, or well, that slanted downward at an angle that in the course of fifty feet, or less, would reach considerably beyond the vertical line of the cave's wall. In shape this shaft was oblong, slightly larger in length and in breadth than the Black Magnet. It was evidently of artificial origin, its four walls being perfectly smooth and without irregularities of line. Even by one who had not seen the magnet descend into this shaft, its intended use as a sort of runway for raising and lowering heavy bodies would be quickly recognized. But where it led to was another matter. One thing was easily discovered: where it reached a point some twenty feet below the level of the cave's floor the shaft was filled with water. Beyond this, of course, nothing could be made out. It was to the bottom of the pool thus indicated that the magnet had plunged.

"It is a well hewn out of the rock by Indians--or perhaps by Spaniards digging for gold," said Leighton.

"I believe that we are the first white people who have ever stood in this place," said Raoul; then added, "unless David Meudon was here three years ago."

"But what is it about?" demanded Miranda impatiently. "What for is the magnet, and this well, and this machine?"

"Pull up the magnet and see for yourself," was the laconic reply.

"Caramba! That will be impossible," protested the doctor, not relishing the prospect of another turn at the machine.

"It is the logical thing to do," agreed Leighton.

The rest shared Miranda's aversion to another bout at the winch; but Leighton, backed by Raoul Arthur, finally persuaded them that their only hope of escape from the cave depended on keeping at this puzzle until they had solved it, and that the first step in this direction was to hoist the Black Magnet from its watery resting place at the bottom of the shaft. Reluctantly obeying the command, they again seized the long handle of the windlass. This time it was fortunate they had Raoul to help them, since the resistance offered by the magnet, which now had to be hauled up an inclined plane by means of a rope nearly one hundred feet in length, was considerably greater than before. The windlass creaked and trembled as revolution after revolution of the drumhead slowly brought the great black bar of metal nearer to the surface. They could hear the far off swirl of the water as the ascending liana vibrated through it. Minutes that seemed to lengthen into hours passed without appreciable result. Then, at last, they heard the water rising as the magnet reached the mouth of the shaft. There was an additional strain on the liana, followed by the noise of a commotion in the subterranean pool as the liquid streams poured back from the emerging body.

But still the end to their work was not in sight. With every turn of the handle the weight of the body at which they were pulling seemed to increase. Mrs. Quayle, sole spectator of what was happening, watched the opening of the well with dismal apprehension, convinced that some dreadful transformation had taken place in its hidden depths. When the top of the magnet finally rose into view she shrieked hysterically. To her notion the great black body had an uncanny look; it had turned into a devil, for aught she knew, filled with evil designs against them. Anything that was supernaturally horrible, she believed, could happen in this cave--and there was enough in her recent experiences, indeed, to give some color to her belief.

But, devil or djinn, the water dripped and splashed in sparkling runlets from the shining body of the Black Magnet that had gained in luster since its submersion in the well. It seemed more alive than before, more capable of exerting the mysterious force that had played such pranks with Mrs. Quayle's jewelry. As it cleared the top of the well the arm of the windlass to which it was hung, as if obeying some invisible signal, detached itself from the socket in the wall and slowly swung back into its original position between the two uprights of the machine. Here, as before, a reverse motion took place. The Black Magnet was poised for a moment in the air. It then descended to the ground, resting, finally, in the same spot where the explorers first discovered it.

A sigh of relief escaped them. Hoisting heavy weights was not much to their taste and they were glad the task was over. Then they rubbed their eyes, half expecting to see something miraculous, some sudden transformation as a result of their labors. But the Black Magnet, except for the brilliance due to its bath in the depths of the earth, looked exactly as it was before. This, it must be confessed, was disappointing to those who had been promised great rewards for toiling so patiently at the windlass. Raoul had declared the experiment would solve the secret of Guatavita. But they failed to see how a wet rock--or bar of metal, whichever it might be--with mud sticking to it, had any connection with a secret. Raoul, however, was not disconcerted. Getting to work on the magnet, he examined minutely every inch of its surface. At first he found nothing. Then, to the amazement of the others, he extracted from one of the large fissures in the magnet a thin disc encrusted with the microscopic growths that form on metals that are long subjected to the action of water. This disc proved its metallic nature by the force needed to release it from the magnet. Much of the brown matter sticking to it was wiped away with a cloth, the more tenacious growth beneath was rubbed and scraped with a sharp stone. When the scouring was finished Raoul triumphantly held up the disc. It was a dazzling plate of gold, thin and flexible, rudely carved to resemble a human being. In size it was not more than the palm of one's hand, somewhat of that shape, a trifle longer and narrower, with a projection, intended to depict a man's head, face and neck, like a pyramid standing on its apex, upon which were traced in embossed lines three loops to represent the mouth and eyes, with another line running down the middle, long and straight, to represent the nose. The body of the figure was similarly carved--raised lines folded over the stomach for arms, with various loops and coils around the neck and chest, intended, doubtless, to indicate the ornaments and insignia of rank worn by the image or, rather, the human being or god for which it stood. All this was done in the finest gold tracery, which, if it lacked some of the subtleties of the goldsmith's art as we know it, was expressed, nevertheless, with admirable delicacy and firmness. In the head of the figure was a round hole showing, doubtless, that the disc was worn as a pendant by its owner, or was hung as a votive offering before his or her household deity.

Leighton had seen figures of like character and workmanship in Bogota, where they were exhibited as ornaments worn by the ancient Chibchas. Usually they were said to have been brought up by divers from the bottom of Lake Guatavita. Hence, there was little doubt as to the origin and antiquity of the disc presented to them by the Black Magnet. But how this disc came to be at the bottom of a well in this vast subterranean labyrinth was not so easily answered. If this disc was the much talked of clew to the lost treasure of the Chibchas, and to all the other mysteries that seemed to crop up at every step the further they went into this cave, it was not an easy one to run down. And then, Miranda, who had insisted all along that by following the direction in which they had been going they were bound to reach the lake, blundered upon the answer to the whole question.

"It is Guatavita!" he said.

Of course, that was it! Herran and Leighton gasped for a moment as they took in the idea, and then they agreed that Miranda was right. Raoul smiled enigmatically as they discussed the problem in detail.

"Well, do you understand it now?" he asked. "Have you discovered Guatavita's secret? I wish I had known it three years ago!" he added bitterly.

"Ah! I see--I see!" shouted the doctor excitedly. "There is the well that come out at the bottom of the lake. Here is the magnet that go down there just when the people throw in all the gold. And then it come back here--and no one know except the king and his family. So, every year, they take all the gold of the country. Ah! they are very wise leetle fellows, those kings!"

"Then, if this is true," said Leighton meditatively; "if this well has its outlet at the bottom of the lake, and was made and used secretly to collect, by means of the Black Magnet, the treasure offered by the people in the Feast of El Dorado, to-day there is no gold left in Guatavita."

"If it were drained of all its waters," remarked Raoul, "I believe that the emptied basin would be found to contain nothing more than a few stray gold ornaments--like the one you fished up just now--that failed to reach the Black Magnet when they were flung into the lake centuries ago."

"Your plans to empty the lake, then, are useless?"

"After what I have learned to-day, added to what I have long suspected, I should say--quite useless."

"But the fabulous amount of treasure those deluded people threw into the lake for centuries----?"

"Has all come up here, where we are standing now, caught by the Black Magnet."

"He fish very well, this leetle stone," said Miranda, caressing it fondly. "He catch more, better fish than the whole world."

"Where is all that gold to-day?" demanded Leighton.

"Ah! Where!"

"Good heavens! What is that?"

While Leighton and Raoul were discussing the old problem of what became of the Chibcha Empire's far-famed treasure, the others had wandered away from the Black Magnet and were examining some of the strange objects in its immediate vicinity. The more familiar they became with this portion of the cave, the more signs they saw in it of human occupation. For one thing, the place was honeycombed with paths, most of them radiating from the shaft that sank to the bottom of Lake Guatavita. These paths led in different directions; but there was no way of telling whether any or all of them had been recently used. This question was of more immediate interest than the one connecting the cave with the fate of the ancient Chibchas. If this cave was inhabited to-day--if it was the hiding place of a lawless gang of Bogotanos, for example--it was well for the explorers to be on their guard. Herran was particularly alive to this possibility, and he was quick to heed, therefore, Mrs. Quayle's terrified exclamation, which she repeated--

"Good heavens! What is that?"

It was at the head of one of the paths, running behind the close ranks of stalactites before which they had found their way from the large open cave beyond, that Mrs. Quayle stood, her eyes round with excitement, pointing vaguely at something in front of her. But the others could see nothing. Indeed, it was hard to tell whether she had really seen anything worth serious investigation, her chronic nervousness had such an uncomfortable habit of discovering specters--that did not exist--in every dark corner. Then, too, clusters of stalactites had a way of taking on odd, fantastic shapes that might easily seem to be alive even to the cool-headed. But this time there really was substance to Mrs. Quayle's fancies. She continued to point down the pathway of stalactites, crying repeatedly--

"What is that?"

"Well, what is it?" demanded Leighton.

"The man in the toga! The man in the toga!" she cried breathlessly.

The others crowded about her.

"It is nothing!" said Miranda incredulously.

"It is! It is!" whispered Una. "I just caught the flash of white drapery at the bend in that farthest corridor."

Raoul laughed. "You are mistaken," he said. "Nothing is there now, that's certain."

They stood silently watching the dark green-and-white figures that stretched away in closely huddled ranks before them. But they could detect nothing that answered to Mrs. Quayle's description. There was nothing that moved, nothing human, in all that glittering array of grotesque forms. Then, there was a sharp, clinking sound, as if the brittle point of a stalactite had been broken off and had fallen to the ground.

"We are watched," said Leighton in a low voice. "Whoever they are, these people have some reason for following us--and keeping out of the way."

"Time to be on our guard," said Herran in Spanish to Miranda, who assented vehemently.

"Nonsense!" exclaimed Raoul.

"Ah! You say that?" growled Miranda suspiciously. "This is one trap of yours, then!"

The accusation added to the general alarm. Raoul protested scornfully; but before he had time to clear himself he was covered by two huge revolvers, drawn simultaneously by Herran and Miranda.

"It is not so easy!" threatened Miranda, whose excited flourish of firearms endangered the others quite as much as it did Raoul.

"Thank heaven, we have guns!" murmured Andrew, who had produced a harmless looking pocket-knife which he brandished ineffectively.