"These quarters do not look much like prison cells, Tommy, but I must admit that we are locked in. Anyhow, I'm not worrying, and we will soon learn our fate and have to be ready to meet it. The people who own this place must have everything they want, and they sure have some scientific knowledge that is not known to us on the surface."

"Wonder if they are humans?"

"Certainly they are. You never heard of wild beasts sleeping in beds like these, did you?"

Tommy laughed at he examined the exquisite hand-wrought figures on the silver bedstead. "No, I didn't," he admitted; "but where on earth did they come from, and what are they doing here?"

"You ask too many questions," replied Frank, shrugging his broad shoulders. "We must simply wait for the answers to reveal themselves."

There was a soft rap at the door of Frank's room, where the two men were talking.

"Come in," called Frank, chuckling at the idea of such consideration from their captors.

A key rattled in the lock and the door swung open to admit the handsomest man they had ever set eyes on. He was taller than Frank by several inches, standing no less than six feet five in his thin-soled sandals, and he carried himself with the air for an emperor. His marble-white body was uncovered with the exception of a loin cloth of silver hue, and lithe muscles rippled beneath his smooth skin as he advanced to meet the prisoners. His head, surmounted by curly hair of ebon darkness, was large, and his forehead high. The features were cla.s.sic and perfectly regular. The corners of his mouth drew upward in a benign smile.

"Greetings," he said, in perfect English and in a soft voice, "to the domain of Theros. You need fear no harm from our people and will be returned to the upper world when the time comes. We hope to make your stay with us enjoyable and instructive, and that you will carry back kind memories of us. The morning meal awaits you now."

So taken aback were the two young Americans that they stared foolishly agape for a s.p.a.ce. Then a tinkling laugh from the tall stranger set them once more at ease.

"You will pardon us, I hope," apologized Frank, "but this is all so unexpected and so unbelievable that your words struck me speechless.

And I know that my friend was similarly affected--We place ourselves in your hands."

The handsome giant nodded understanding. "No offense was taken," he murmured, "since none was intended. And your feelings are not to be wondered at. You may call me Orrin."

He turned toward the open door and signified that they were to follow him. They fell in at his side with alacrity, both suddenly realizing that they were very hungry.

They followed in silent wonderment as Orrin led the way to a broad balcony that overlooked a great underground city--a city lighted by the soft glow from some vast lighting system incorporated in its vaulted ceiling high overhead. The balcony was many levels above the streets, which were alive with active beings of similar appearance to Orrin, these speeding hither and yon by means of the many lanes of traveling ways of which the streets were composed. The buildings--endless rows of them lining the orderly streets--were octagonal in shape and rose to the height of about twenty stories, as nearly as could be judged by earthly standards. There were no windows, but at about every fifth floor there was an outer silver-railed balcony similar to the one on which they walked. The air was filled with bowl-shaped flying ships that sped over the roof tops in endless procession and without visible means of support or propulsion. Yet the general effect of the busy scene was one of precise orderliness, unmarred by confusion or distracting noises.

Orrin vouchsafed no explanations and they soon reentered the large building of which the balcony was a part. Here they were conducted to a sumptuously furnished dining room where their breakfast awaited them.

During the meal, which consisted of several courses of fruits and cereals entirely strange to Frank and Tommy, they were tended by Orrin with the utmost deference and most painstaking attention. He antic.i.p.ated their every want and their thoughts as well. For, when Frank endeavored to ask one of the many questions with which his mind was filled, he was interrupted by a wave of the hand and a smile from their placid host.

"It is quite clear to me that you have many questions to propound,"

said Orrin, "and this is not a matter of wonder. But it is not permitted that I enlighten you on the points you have in mind. You must first finish your meal. Then it is to be my privilege to conduct you to the presence of Phaestra, Empress of Theros, who will reveal all. May I ask that you be patient until then?"

So friendly was his smile and so polished his manner that they restrained their impatience and finished the excellent breakfast in polite silence.

And Orrin was as good as his word, for, no sooner had they finished when he led them from the room and showed the way to the elevator which conveyed them to the upper floor of the building.

From the silver-grilled cage of the lift they stepped into a room of such beauty and magnificence of decoration that they gazed about them in wondering admiration. The paneling and mouldings were of hammered silver that gleamed with polished splendor in the soft rose glow of the hidden lights. The hangings were of heavy plush of deep green hue and bore intricate designs of silver thread woven into the material.

At the opposite side of the room there was a pair of huge double doors of chased silver and on either side of this pretentious portal there stood an attendant attired as was Orrin, but bearing a silver scepter to denote his official capacity.

"Phaestra awaits the visitors from above," intoned one of the attendants. Both bowed stiffly from the waist when Orrin led the two young scientists through the great doors which had opened silently and majestically at their approach.

If the outer room was astonishing in its sumptuousness of decoration and furnishing, the one they now entered was positively breath-taking.

On every side there were the exquisite green and silver hangings.

Tables, divans, and rugs of priceless design and workmanship. But the beauty of the surroundings faded into insignificance when they saw the empress.

A canopied dais in the center of the room drew their attention and they saw that Phaestra had risen from her seat in a deeply cushioned divan and now stood at its side in an att.i.tude of welcome. Nearly as tall as Frank, she was a figure of commanding and imperious beauty.

The whiteness of her body was accentuated by the silver embroidered and tightly fitted black vestments that covered yet did not conceal its charms. A halo of glorious golden hair surmounted a head that was poised expectantly alert above the perfectly rounded shoulders. The exquisite oval of her face was chiseled in features of transcendent loveliness. She spoke, and, at sound of her musical voice, Frank and Tommy were enslaved.

"Gentlemen of the upper world," she said gently, "you are welcome to Theros. Your innermost thoughts have been recorded by our scientists and found good. With a definite purpose in mind, you learned of the existence of the silver dome of Theros, yet you came without greed or malice and we have taken you in to enlighten you on the many questions that are in your minds and to return you to mankind with a knowledge of Theros--which you must keep secret. You are about to delve into a mystery of the ages; to see and learn many things that are beyond the ken of your kind. It is a privilege never before accorded to beings from above."

"We thank you, oh, Queen," spoke Frank humbly, his eyes rivetted to the gaze of those violet orbs that seemed to see into his very soul.

Tommy mumbled some commonplace.

"Orrin--the sphere!" Phaestra, slightly embarra.s.sed by Frank's stare, clapped her hands.

At her command, Orrin, who had stood quietly by, stepped to the wall and manipulated some mechanism that was hidden by the hangings. There was a musical purr from beneath the floor, and, through a circular opening which appeared as if by magic, there rose a crystal sphere of some four feet in diameter. Slowly it rose until it reached the level of their eyes and there it came to rest. The empress raised her hands as if in invocation and the soft glow of the lights died down, leaving them in momentary darkness. There came a slight murmur from the sphere, and it lighted with the eery green flickerings they had observed in the dome of silver.

Fascinated by the weaving lights within, they gazed into the depths of the crystal with awed expectancy. Phaestra spoke.

"Men from the surface," she said, "you, Frank Rowley, and you, Arnold Thompson, are about to witness the powers of that hemisphere of metal you were pleased to term 'Silver Dome.' As you rightly surmised, the dome is of silver--mostly. There are small percentages of platinum, iridium, and other elements, but it is more than nine-tenths pure silver. To you of the surface the alloy is highly valuable for its intrinsic worth by your own standards, but to us the value of the dome lies in its function in revealing to us the past and present events of our universe. The dome is the 'eye' of a complicated apparatus which enables us to see and hear any desired happening on the surface of the earth, beneath its surface, or on the many inhabited planets of the heavens. This is accomplished by means of extremely complex vibrations radiated from the hemisphere, these vibrations penetrating earth, metals, buildings, s.p.a.ce itself, and returning to our viewing and sound reproducing spheres to reveal the desired past or present occurrences at the point at which the rays of vibrations are directed.

"In order to view the past on our own planet, the rays, which travel at the speed of light, are sent out in a huge circle through s.p.a.ce, returning to earth after having spent the requisite number of years in transit. Instantaneous effect is secured by a connecting beam that ties together the ends of the enormous arc. This, of course, is beyond your comprehension, since the Ninth Dimension is involved. When it is desired that events of the present be observed, the rays are projected direct. The future can not be viewed, since, in order to accomplish this, it would be necessary that the rays travel at a speed greater than that of light, which is manifestly impossible."

"Great guns!" gasped Frank. "This crystal sphere then, is capable of bringing to our eyes and ears the happenings of centuries past?"

"It is, my dear Frank," said Phaestra, "and I would that I were able to describe the process more clearly." She smiled, and in the unearthly light of the sphere she appeared more beautiful than before, if such a thing were possible.

On the pedestal which supported the sphere there was a glittering array of dials and levers. Several of these controls were now adjusted by Phaestra, the delicate motions of her tapered fingers being watched by the visitors with intense admiration. There came a change in the note of the sphere, a steadying of the flickerings within.

"Behold!" exclaimed Phaestra.

They gazed into the depths of the sphere and lost all sense of detachment from the scene depicted therein. It seemed they were at a point several thousand miles from the surface of a planet. A great continent spread beneath them, its irregular sh.o.r.e line being clearly outlined against a large body of water. Here and there the surface was obscured by great white patches of clouds that cast their shadows below.

"Atlantis!" breathed Phaestra reverently.

The lost continent of mythology! The fabled body of land that was engulfed by the Atlantic thousands of years ago--a fact!

Tommy glanced at Frank, noting that he had withdrawn his gaze from the sphere and was devouring Phaestra with his eyes. As if drawn by the ardor of his observation, she raised her own eyes from the sphere to meet those of the handsome visitor. Obviously confused, she dropped her long lashes and turned nervously to the controls. Tommy experienced a sudden feeling of dread. Surely his pal was not falling in love with this Theronian empress!

Then there came another change in the note of the sphere and once more they lost themselves in contemplation of the scene within. The surface of the lost continent was rushing madly to meet them. With terrific velocity they seemed to be falling. An involuntary gasp was forced from Tommy's lips. Mountains, valleys, rivers could now be discerned.