“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.