Miranda and, in a lesser degree, those who were with him in the palace garden, were indignant at their enforced separation from Una and Sajipona. The doctor, priding himself especially on Raoul’s discomfiture, considered the queen guilty of the basest ingratitude, and even suspected that she might be, at that moment, plotting their destruction. Leighton and Herran scoffed at this, but it appealed to Mrs. Quayle, and that lady, clinging nervously to Andrew, followed Miranda’s explosive talk with appreciative horror. This proving a profitless diversion, however, Leighton proposed the adoption of a plan for immediate action. An attack on the palace, or a retreat that would bring them to the entrance of the cave, were alternately considered. But as both plans seemed to leave Una out of their reach, they were discarded as impossible, and it looked as if they would have to settle down to an indefinite stay in the garden. In the midst of the discussion the doors of the palace were thrown open and Narva and Una hurried out to meet them. Still fearing ambuscades and other undefinable treacheries, Miranda was by no means ready to throw aside his caution at their approach. But the aged sibyl’s lofty disdain was disconcerting, nor was there any resisting the whole-hearted joy with which Una greeted them.

To their eager inquiries she gave the briefest replies. For one thing, she assured them that they had Sajipona’s promise that their escape from the cave would be easy and not too long delayed. Of the queen’s friendly disposition towards them, she said, there was not the slightest doubt. They could count on the carrying out of her promise if, on their side, the conditions she proposed were observed. These conditions were: never, once they were out of it, to enter the cave again; to reveal as little as possible to the outside world of their experiences during their present adventure; and to keep an absolute silence regarding Sajipona’s relationship to this mysterious race of people.

Beyond this Una would say little. The conditions were joyfully accepted. Nothing, certainly, could ever induce them to enter the cave again. But then—there was David. Yes, Una admitted, David was in the palace. She had seen him. He was free, so far as she knew, to come or go as he chose. But he had not said he would return with them. It might be, indeed, that he would choose to live permanently with the cavemen—an amazing possibility that started an avalanche of questions to which only the vaguest answers were given. Doubtless they would see David before they left, Una assured them, and learn for themselves all they wished to know. As for Raoul, she could tell nothing. He was, apparently, in favor with the queen, and engaged in some undertaking for her.

Una betrayed none of her suspicions regarding David in her discussion of these matters. She had not seen him since that first meeting in the little portico adjoining his quarters in the palace, hence she was ignorant of the result of Raoul’s experiment. Sajipona had come to her immediately after its conclusion and, judging by the quiet cheerfulness of her manner, she fancied everything had gone to her satisfaction. This was confirmed by the announcement of the festival that was shortly to take place. This festival, Una had been told, was to be the occasion for great rejoicing among the cave people. It was a sort of national day, a celebration that had not been held in many a long generation. It was intended to recall, she heard, the ancient feast of El Dorado, the Gilded Man, about which, of course, as it existed among the Chibchas before the period of the Spanish invasion, Una was familiar through the traditions as told by David and Leighton. What form this revival of the old ceremonies would take had not been explained. But it piqued her curiosity and, in spite of resentment and wounded pride, she cherished a secret hope that it would bring about a final understanding of David’s position in regard to Sajipona and herself. She felt sure David would be at the festival, and she had an intuitive feeling as well that his presence would dispel the mystery that sundered them. She did not look for, nor did she consciously want a reconciliation. Bitterly she denied herself the possibility of one. But she wished to know definitely, and to its full extent, David’s faithlessness to her. After she had learned this, they could not start on their homeward journey too quickly.

Still absorbed in these reflections, Una and her companions, under Narva’s lead, entered the great court of the palace. Una, of course, had grown familiar with the strange features to be found in this hall of marvels; but the others, entering it for the first time, were amazed at what they saw there. In Leighton this feeling of wonder reached its highest pitch. The shattering of one scientific belief after another that he had experienced ever since entering the cave left him, it is true, somewhat callous to new impressions. But this apathy, if it can be called that, melted away as he stood beneath the great white dome that soared in flashing lines above them. Looking up at the huge ball of fire suspended just beyond the apex of this dome, for a moment he remained speechless. Then, turning to his companions, he voiced the ecstasy that comes with some unexpected, epoch-making discovery.

“Do you know what that is?” he demanded.

No one did. Miranda shrugged his shoulders and turned his attention ostentatiously elsewhere, as if floating balls of crackling white flames, used to illuminate caves, were matters of ordinary experience with him. Andrew’s mouth was opened quite as wide as his eyes as he stood staring upward at the curious illumination. It would be a splendid saving of candle power, he thought, more than enough for the whole village, if they could only manage to take it back with them to Rysdale. But, even if it were small enough, it wouldn’t be possible to carry in one of their trunks, since it would be sure to set things on fire. This objection was made by Mrs. Quayle, and seemed reasonable enough.

“That is the most remarkable thing on earth,” went on Leighton, heedless, in his excitement, of the frivolous comments of his companions. “I have often thought that sooner or later something like this would be discovered. It is impossible to estimate its value. Why, all the billions of dollars that there are in the world to-day could not pay for it at the present market prices.”

The calm assurance with which this estimate was given shattered Miranda’s pose of studied indifference.

“What is it?” he asked sharply.

“Radium!”

The silence that followed was eloquent of the mingled incredulity and delight with which so staggering an announcement was received. Leighton, fascinated with his subject, proceeded to explain things, much as if he were at home again in his laboratory, working out a particularly novel experiment, and expounding his various theories of physics. Of course, he had nothing but theory to go on, since he had never seen, heard of, or believed possible such a huge mass of radium as this that hung above them. And because it was so unbelievably huge, the others refused at first to take it for what he said it was. But he insisted that it could be nothing else. Radium it was—and with this as his basis of fact, he quickly built up an imposing theory that he used to explain more than one matter that before had puzzled them.

This immense globe of radium, he believed, in the first place, was the parent-body of all the infinitesimal particles of this remarkable substance that had recently been found in different parts of the world. The mysterious properties of radium, he said, were only dimly understood as yet by physicists who had experimented with it. Apparently it was a mineral; but as it revealed a constant and amazing activity, throwing out a force that so far had baffled analysis, there were those who held that it was a living, or, better yet, a life-giving substance. The existence of this immense body of radium here, in the center of the cave, explained, to the satisfaction of Leighton, much of the strange phenomena they had seen. Here, obviously, was the source of the soft, diffused light that had puzzled them ever since they passed through the Condor Gate; and it was to this center of energy that they must attribute the increase in buoyancy and physical well-being experienced the further they penetrated into this subterranean world. The peculiar growths, also, half vegetable, half mineral, that had given the appearance of groves and gardens to certain portions of the cave through which they traveled, were undoubtedly due to this marvelous force, occupying the same relative position towards subterranean life that the sun did to the outside world of nature. Moreover, Leighton firmly believed that the supremacy of radium as the life-giver in this cave, involved the existence, as they would discover, of other phenomena having still more subtle, even psychic, qualities. Narva grunted significantly at this observation, and Una confirmed the truth of it by relating how the floor of the court where they were standing had, only a short time before, reflected a series of pictures of events taking place in the outside cave, by means of which they had been able to follow Leighton’s approach to the palace and watched the collision of his party with that of Raoul. It was through this peculiar photographic power of radium, indeed, that Sajipona could discover whatever was taking place in the remotest regions of her domain. This information did not surprise Leighton in the least. On the contrary, he appeared to take it as a matter of course, one of many marvels that might be expected in a land run, so to speak, by radium.

Absorbed in the discussion of these matters, no one noticed the entrance of Sajipona. The queen, coming from the apartment where she had left David and Raoul, was not in a hurry to make her presence known, and lingered long enough behind the others to enjoy the curiosity and wonder with which they were regarding the globe of light above them. She now advanced smilingly, addressing herself particularly to Leighton, whom she complimented for his shrewd guess as to the nature of the force pervading and governing the cave. Indian though she was, inheritor of a realm that, in all its customs and beliefs, was primitive, distant from the civilizations found elsewhere in the world to-day, she had heard and studied enough of Europe and America to be familiar with some of the momentous discoveries of modern science. Hence, she had been quick to grasp the fact that this subterranean sun, worshiped by her ancestors ages ago as the Life Giver—the God that, according to Indian legend, resided under Lake Guatavita—was nothing more nor less than an immense body of radium, the most precious substance known to man, the scarcity of which had led scientists to ransack the uttermost parts of the earth in the hope of adding to their store of it. Here it had always been, the one priceless possession of her people, enabling them to live apart, independent of the world that threatened at one time to exterminate them. How this radium had come there originally she could not tell. It was the result, doubtless, of hidden forces about which philosopher and scientist are as yet ignorant. Or, it might itself be the architect of the subterranean world whose extent and manifold marvels had amazed the explorers. By means of this radium force, as Una had told them, she was able to see what was happening in any part of the cave, even throughout that dark region lying beyond the Condor Gate—an incredible statement, as it appeared to Leighton. For they had been in this outer cave and discovered in it neither the light nor the warmth they had enjoyed on this side the Condor Gate. Hence, argued the savant, this outer cave appeared to lie entirely beyond the zone of radium influence. Sajipona smiled at Leighton’s objection and asked him if nothing had occurred in the outer cave, while he was there, that he had been unable to explain. They had been through so many marvels in so short a time that the explorers looked at each other doubtfully. Mrs. Quayle answered for them.

“Yes, the terrible stone that pulled off my jewelry, and then dragged gold up from the lake outside—how was that done?” she asked, still smarting, apparently, from the indignities she had suffered.

“Oh, that was merely a powerful magnet that attracts gold instead of iron,” explained Sajipona, as if such trifling matters were scarcely worthy to be ranked with the other marvels of the cave. “This magnet played a great part, centuries ago, in gathering together all the wealth of my ancestors from the Sacred Lake where it had been cast during the Feast of the Gilded Man. To-day it is never used because all the gold has been taken out of the lake. But—was there nothing else mysterious?”

“Caramba!” ejaculated Miranda, “I know! When we come in from the outside, all is open; we can come in and we can come out. And then, this little old woman is frighten, and I take her out. That is, I think I take her out. But the wall is shut, and we cannot see where it is. We are in prison. Who did that? There is no one there.”

Sajipona laughed.

“Yes, that is it! No one was there—except Radium, the influence from the great globe hanging above us. Here, you see, it does many more things than it does in your outside world. It is really the eye of the cave—and sometimes the arm. Although its light does not, as you know, extend into the outer cave, it reflects here, within this circle, whatever is lighted up beyond there. When you came in with your torches I was able to follow you by this means—very obscurely, of course, because torches throw only a small circle of light. I could hardly make you out, but I felt sure who you were. I was expecting you. And then, because I needed you here and feared you might grow tired of so long a journey, I shut the entrance to the cave so you could not escape. That is where radium works like an arm. It can carry an electric force, an irresistible current, without using wire. For our own safety we have this force connected with the entrance to the cave. When that entrance is open and we want to close it, this force is released and moves a great rock that glides into place across the passageway, where it seems to be a part of the wall on either side.”

This dissertation from Sajipona on the uses to which radium had been put in her kingdom was amazing enough to Leighton’s trained, careful mind. In his own studies of radium activity he had failed to find any indication of the possibility even for the development of the sensational features that were now given to him as accomplished, familiar fact. For one thing, science was restricted in its experiments by the small quantity of radium within its reach. Here the amount, estimating the size of the fiery globe above him, was measured by the hundreds of tons—a fact, of course, that must greatly increase the field over which radium might be made to operate. Nevertheless, except for this vague theory that an unknown power could be developed from a great mass of this marvelous substance, suspended in a great chamber, or series of chambers, not subject to the ordinary outside influences of heat and light and air, it was difficult to find a reasonable explanation for the things that Sajipona told him and that he himself had seen. Most astounding it was, also, to a modern scientist, brought up in the methods and limited by the views of his age, to discover here a development in physics, beyond the dreams of the most daring investigator, that actually belonged to a primitive race, and was first practiced by them in a period and country without scientific culture. The whole affair, indeed, furnished an instance where science seemed to overstep the borderland of the miraculous. It was as marvelous, after all, as the familiar achievements of wireless or the cinema would have been if suddenly presented to the world of half a century ago.

Enjoying the savant’s bewilderment, Sajipona described more of the cave’s wonders. Her forefathers, she said, had discovered a way to imitate the changes from day to night by a simple process of veiling and unveiling the ball of radium. This was found necessary in order to create the right variations between growth and a state of rest in vegetation. When circumstances made it desirable to use the cave as a permanent habitation, it was found that this variation from light to darkness was indispensable to human welfare. Without it there could be little of the happiness that comes from the storing up and the subsequent expenditure of human energy. Discovering this, certain wise Indians among the cavemen of the past made further experiments in the regulation of light and heat. Among other things, these pioneers in a new science found that the color rays emanating from radium had different properties—some being more life-giving than others—and that by controlling these rays it was possible to create and develop various kinds of subterranean plants. They firmly believed, also, that by working along these lines it would be possible to arrive at new animal forms. Some remarkable experiments were made in this direction, but the results were too indefinite for practical purposes. The whole problem was therefore abandoned years ago, its unpopularity having been increased by the religious prejudice excited against it. This intrusion of what he regarded as blind superstition upon the profitable labors of science incensed Leighton, who muttered imprecations on the idolatries of barbarians. But in this he was checked by Sajipona, who declared that the religious beliefs of her people were in no sense more idolatrous than many of the beliefs current in the outside world. They had their fantastic legends, it is true—like the story of the god who, through the ascendancy of an evil rival, had been imprisoned for ages at the bottom of the Sacred Lake, whence he had been released by the prayers and sacrifices of his followers. Such legends the more enlightened regarded purely as fables, within which were conveyed certain truths that were of lasting value to mankind. The ignorant probably failed to recognize these truths underneath their coverings of legend. But it was not merely the ignorant, it was those who possessed a higher religious sense who were revolted by the effort to create animal life through artificial means. This feeling of antagonism arose simply because in the last of the experiments attempted by the Indian wise men, certain forms were developed, giving feeble signs of life, and indicating unmistakably that if they were ever endowed with a complete, independent existence, they would become a race of malevolent beings, a menace to all existing institutions and peoples. Hence, these wise men were counseled by the more practical and simple-minded of their contemporaries to abandon the rÔle of creator, leaving the production of life to the rude and bungling methods to which Nature was accustomed. They were loath to yield in this, but public opinion became too strong for them; the religious element conquered—and these savants of old turned their attention to a new problem that had already been suggested by their partial experiments in the creation of life, and that promised something really worth while. This new problem involved the regulation of man’s moral and intellectual natures, not through the teaching of ideas, but by the employment of physical and chemical forces.

It had been discovered long before that the Radium Sun controlled the subterranean life coming within its influence. But as this sun was itself capable of regulation, many novel—and safe—departures in human development were made possible by an intelligent practice of the new solar science. Here again, as in the experiments with plants, it was the variation of colors, of light and darkness, that furnished the key to what the Indian savants were after. Thus, it was learned that certain radium colors had an affinity for certain moral attributes. These moral attributes could, for this reason, be greatly increased by placing the man or woman to be operated on in a properly regulated color bath. Unfortunately, these wise men had not continued their experiments with this Theory of Colors after reaching the first few crude results. They lost interest in the subject when its intensely practical nature became apparent. Hence, a complete classification of all the colors and combinations of colors, with their moral and intellectual affinities, was still lacking. But enough was discovered to be of real, positive benefit in the education of the cavemen and in keeping order among them. People who were harassed by domestic troubles, for instance, were put through a course of color treatment; wives who were tempted to leave their husbands, or husbands who got tired of their wives (as, it seems, they sometimes did in the Land of the Condor) were plunged into color-baths, varied according to the exact nature of the complaint from which they were suffering, and kept in these baths until they were brought back to a reasonable frame of mind. And then, in matters that affected the well-being of the whole community—matters that in the outside world would give rise to various political panaceas—it was a simple application of the Color Theory that would straighten things out. It was found, for instance, that yellow rays from the Radium Sun stimulated generosity. Thus, in the case of a man whose intense acquisitiveness threatened to monopolize the wealth of the community, a steady application of yellow rays was sure to be beneficial, if not to him, at least to those about him.

A case of this kind, indeed, had been recently operated on in this way. The patient had accumulated such vast wealth that he had grown to be a public inconvenience. As his business dealings, however, did not come within reach of the criminal law, and as his wealth was thus due to his natural bent for finance, the courts could not touch him. He was, therefore, placed—not by way of punishment, but as a mark of public esteem—in a bath of yellow light. The effect was extraordinary and bore out all the claims of the originators of the Color Theory. He had not been in this yellow bath more than a few hours before he began to part with his wealth. On the second day he became more reckless in his benefactions, and this frenzy for giving away what he had before so jealously guarded from his neighbors, increased at so rapid a rate that by the end of a week his entire fortune had passed, through his own voluntary act, into the hands of the government and various benevolent institutions. When he had nothing more to give, it was decided that he had had enough of the yellow treatment. He was then released from the honors the State had showered upon him, and passed the rest of his life rejoicing in his penniless condition.

Then, there was the case of a man who had grown tired of his wife, and who had outraged the sense of the community by leaving her. He was captured and placed in a bath of green light. In a very short time he got over his roving propensities and became so persistent in his attentions to his wife that, in order to give her some peace, he was put into another bath having a slightly neutralizing effect on the first, or green, bath. Thus, the marital troubles of this couple were completely and finally straightened out and they lived amicably together without the tiresome intervention of mutual friends, or of the law courts.

The interesting possibilities of this Color Theory in penology and in the regulation of domestic affairs, did not escape Leighton. He had himself believed that in the latest discoveries in physics there might be found a connecting link between the science of matter and the science of mind. His natural skepticism, however, did not allow him to accept too readily all of Sajipona’s amazing statements. He doubted her real knowledge of these abstruse subjects. She spoke of these matters, indeed, crudely, not with the familiarity as to detail of a trained scientist. What she said had all the simplicity, and much of the fantastic absurdity, of a fairy tale. But beneath its extravagance there was enough substance to her story, and the theory upon which it was based, to make it worthy a scientist’s consideration. For one thing, it changed completely the notion Leighton had already formed of this subterranean world. The story, for instance, of the chastened millionaire took into account a complex social system that was utterly unthinkable in a region so confined territorially, so limited, by reason of its peculiar situation, as regards human activity, as this so-called Land of the Condor. The inhabitants of the cave, from what he had seen of them—in the straggling village they had passed through with Narva, and among the followers of Raoul—gave no indication of a culture superior to that shown by people just emerging from savagery. These cavemen, certainly, had not reached that stage of enlightenment from which is developed the millionaire capitalist of whose interesting ventures in monopoly Sajipona had told them. In the ill-fated Anitoo, however, and his men, and in the people surrounding Sajipona, there was evidence of social and mental superiority. The two men who served as the queen’s ambassadors in the garden, and who were distinguished from the rest by their red robes, belonged either to a priesthood, or to some order that placed them intellectually above the common rank. They were undoubtedly learned far beyond the Indian average. One of them, indeed, was with Sajipona in the court, and prompted her more than once during her explanation of the Radium Sun and its uses. He spoke in a low voice, and in a language unintelligible to the Americans. From his bearing and fluency of speech, Leighton concluded that he was one of the commonwealth’s so-called “wise men,” an investigator, possibly, in those physical and psychological phenomena that held out such tantalizing promise of new conquests in the domain of human knowledge.

Sajipona was quick to perceive the difficulties arising in Leighton’s mind in regard to her narrative, but she referred to another occasion a description of the science, religious beliefs, social institutions and customs of the subterranean people. In attempting such a task, she declared that the priest at her side, whom she addressed with befitting reverence as Omono, Teacher of Mankind, would be far more capable than she. For it was Omono, with his companion, Saenzias, who received and carried out the laws and traditions of their race—always subject, of course, to her own authority—and it was by them that these laws were further perfected before being passed on to the two priests who would succeed them in administering the affairs of the kingdom.

“You are puzzled, naturally,” she said, “to hear of the existence of wealth and poverty, charitable institutions and governments, science and religion, in a kingdom whose boundaries are within the walls of a cave. But you have seen only a small part of this Land of the Condor. On every side it extends many miles further underground. And in the South from here, not a great distance, there is a vast region—unknown to the rest of the world—filled with mountains, fertile valleys, rivers, and bodies of water strewn like jewels over plains that yield an abundance sufficient for all mankind. This land is at the mouth of our subterranean world. It lies in the heart of that region marked ‘unexplored’ by your mapmakers. We have no fear that it will ever pass from our hands, that it will ever be more than a blank patch on your maps, for on every side it is defended by unscalable cliffs of snow and ice. It can be reached only through this ancient cave. Perhaps, in the ages to come, when the people of the outside world and of this race that has lived here in an unbroken line as far back as the memory of man can go, have been perfected, these barriers will be thrown down. Such has been the prophecy of some of our wise men; and to-day Omono and Saenzias tell us that this final period of perfection is rapidly approaching. It may be that before you go out again into your own world, you will see more of the wonders of this Land of the Condor, and of the unknown Land of the Sun that lies at its door. There are cities out there, built with an art that is only rudely possible in our underground home. Here, you are amazed at the cunning of some of our work. You wonder that a race of moles could conjure wealth and beauty out of a cavern that is never opened to the airs of heaven. But in our Land of the Sun there are marvels far greater than these. In both regions you will see the work of the same people; but here where you stand is the center of our race, or—as you would call it—our seat of government. It is here, because of the Radium Sun above us, that we find our strength. But it is outside, in the Land of the Sun, that the millions who call me their queen, are working out the destinies of future generations. Before these last years your people and our people have kept apart. You were ignorant of our existence, and we held aloof from you, remembering the cruelty and injustice of which you were guilty centuries ago. But the time has come, so Omono and Saenzias declare, when our two worlds must venture the first step in the knowledge of each other. Through me this experiment will take place. You are instruments in it. To-day decides the success or failure of our plan. The wealth of our kingdom we have guarded all these centuries, not for ourselves only. To increase it we must share it with the outside world. But if the outside world is not ready, if it still exists merely to plunder the wealth others have gathered, we will wait, if need be, for another flight of centuries.”

Sajipona’s announcement aroused an immense curiosity among the explorers. What did she mean? they asked each other. How was this working out of their mutual destinies to be accomplished at this particular time and through them? From Narva they had heard vaguely of a festival that was to be celebrated—and now they learned that the hour for it was at hand. Sajipona told them this, and as the information followed immediately upon what she had let them know of her aspirations regarding the future of her people, they concluded that in some mysterious way, the festival and the fate of this subterranean kingdom were bound together. They waited to hear more but, apparently, Sajipona had finished all she had to say to them. Turning to Una, she led her apart from the others. The two talked earnestly together, the one protesting, the other entreating. Finally, Sajipona appeared to succeed in her request, whatever it was, and taking Una’s hand walked with her to a distant part of the hall. Here a door was thrown open. Una entered the apartment beyond, the door closing behind her. It was all so quickly done, the others barely realized that Una had left them before they were rejoined by Sajipona, who spoke to them as if nothing had happened.

“Let us go,” she said. “The festival is ready. There is no time to lose.”