Johnston and Branasko looked down at the great ball of light below them in silent wonder. Johnston was the first to speak. He pointed to the four massive cables which supported the sun at each corner of the platform and extended upward till they were enveloped in the darkness.

“They hold us up,” he said, “where do they go to?”

“To the big trucks which run on the tracks near the roof of the cavern; the endless cables are up there, too, but we can not see them with this glare about us.”

“We can see nothing of Alpha from here,” remarked Johnston disappointedly, “we can see nothing beyond our circle of light.”

“I should like to look down from this height at night,” said the Alphian. “It would be a great view.”

“What is this?” Johnston went to one side of the platform and laid his hand on the spokes of a polished metal wheel shaped like the pilot-wheel of a steamboat. Branasko hastened to him.

“Don't touch it,” he warned. “It looks as if it were to turn the electric connection off and on. If the sun should go out, the consequences would be awful. The people of Alpha would go mad with fear.”

The American withdrew his hand, and he and Branasko walked back to the centre of the platform. Johnston uttered an exclamation of surprise. “The light is changing.”

And it was, for it was gradually fading into a purple that was delightfully soothing to the eye after the painful brightness of a moment before.

“I understand,” said the Alphian, “we are running very slow and are only now about to approach the great wall, for purple is the color of the first morning hour.”

“But how is the light changed?” asked Johnston curiously.

“By some shifting of glasses through which the rays shine, I presume,” returned the Alphian; “but the mechanism seems to be concealed in the walls of the globe.”

Not a word was spoken for an hour. They had lain down on the platform near the iron railing which encompassed it, and Branasko was dozing intermittently. Again the light began to change gradually. This time it was gray. Johnston put out his hand to touch Branasko, but the Alphian was awake. He sat up and nodded smiling. “Wait till the next hour,” he said; “it will be rose-color; that is the most beautiful.”

Slowly the hours dragged by till the yellow light showed that it was the sixth hour. Branasko had been exploring the vast interior below and came back to Johnston who was asleep on the floor of the platform.

“I have just thought of something,” said Branasko. “This is the day appointed by the king to entertain his subjects with a grand display of the elements.”

“I do not understand,” said Johnston.

“The king,” explained the Alphian, “darkens the sun with clouds so that all Alpha is blacker than night, and then he produces great storms in the sky, and lightning and musical thunder. We may, perhaps, hear the music, but we cannot witness the storm and electric display on account of the light about us. It usually begins at this hour; so be silent and listen.”

After a few minutes there was a rumble from below like the roar of a volcano and an answering echo from the black dome overhead. This died away and was succeeded by a crash of musical thunder that thrilled Johnston's being to its very core. Branasko's face was aglow with enthusiasm.

“Grand, glorious!” he ejaculated, “but if only you could see the lightning and the dawn in the east you would remember it all your life. The sunlight is cut off from Alpha by the clouds, and there is no light except the wonderful effects in the sky.”

Johnston had gone back to the wheel and was examining it curiously.

“I have a mind to turn off the current for a moment anyway,” he said doggedly; “if the sun is hidden they would not discover it.”

Branasko came to him, a weird look of interest in his eyes. “That is true,” he said; “besides, what matters it? We may not live to see another day.”

Johnston acted on a sudden impulse. He intended only to frighten Branasko by moving the wheel slightly, and he had turned it barely an eighth of an inch, when, as if controlled by some powerful spring, it whirled round at a great rate, making a loud rattling noise. To their dismay the light went out.

“My God! what have I done?” gasped the American in alarm.

“Settled our fate, I have no doubt,” muttered the Alphian from the darkness.

Johnston had recoiled from the whirling wheel, and now cautiously groped back to it, and attempted to turn it. It would not move.

“It has caught some way,” he groaned under his breath.

“And we have no light to find the cause of the trouble,” added the Alphian, who had knelt down and was feeling about the wheel. Presently he rose.

“I give it up,” he sighed, “I cannot understand it. The machinery is somewhere inside.”

“It has grown colder,” shuddered Johnston.

“We were warmed by the light, of course,” remarked Branasko, “and now we feel the dampness more. We are going at a frightful speed.”

Just then there was a jar, and the sun swung so violently from side to side that the two men were prostrated on the floor. The speed seemed to slacken.

“I wonder if we are going to stop,” groaned the American, and he sat up and held to Branasko. “Perhaps they will draw us back to rectify the mistake, and then——”

“It cannot be done,” interrupted the Alphian. “The machinery runs only one way. We shall simply have to finish our journey in darkness.”

“They may catch us on the other side before the sun starts back through the tunnel,” suggested the American.

“Not unlikely,” returned Branasko. “There, we are going ahead again. One thing in our favor is that we can more easily escape capture in darkness than if the sun were shining.”

“Does the sun stop before entering the tunnel?”

“I do not know,” replied Branasko; “perhaps somebody will be there to see what is wrong with the light. We must have our wits about us when we land.”

Johnston was looking over the edge of the platform. “If the king's display is taking place down there I can see no sign of it.”

“How stupid of us!” ejaculated Branasko. “Of course, clouds sufficiently dense to hide the sun from Alpha would also prevent us from seeing the display below. I ought to——”

He was interrupted by a grand outburst of harmony. The whole earth seemed to vibrate with sublime melody. “Our blunder has not been discovered yet,” finished Branasko, after a pause, “else the fete down below would have been over. I am cold; shall we go inside?”

Johnston's answer was taken out of his mouth by a loud rattling beneath the floor, near the wheel he had just turned; the sun shook spasmodically for an instant, and its entire surface was faintly illuminated, but the light failed signally.

“It must have been an extra current of electricity sent to relight the lamps,” remarked Johnston; and, as he concluded, the sun trembled again, and another flash and failure occurred. “Look,” cried the American, “the clouds are thinning; see the lights below! They have discovered the accident!”

They both leaned over the railing and looked below. As far as the eye could reach, within the arc of their vision, they could see fitful lights flashing up, here and there, and going out again. And then they heard faint sounds of crashing masonry and the condensed roar of human voices, which seemed to come from above rather than from below. The Alphian turned. “I cannot stand the cold,” he said.

Johnston followed him. The rapid motion of the swinging sphere made him dizzy, and he caught Branasko's arm to keep from falling.

“How can we tell when we go over the wall?” he asked anxiously.

“We shall have to guess at it,” was the answer. “At any rate we must be near the lower door so as to get out quickly if it is necessary to do so to escape detection.”

In the darkness they slowly made their way down the stairs to the great room.

“There ought to be some way of making a light,” said the Alphian, and his voice sounded loud and hollow in the empty chamber. After several failures to find the stairs they descended to the door they had entered. Branasko opened it a little, and a breeze came in. They sat down on the stone, and after a while, in sheer fatigue, they fell asleep. Hours passed. Branasko rose with a start, and shook Johnston.

“Our speed is lessening,” he exclaimed. “We must be going down. Be ready to jump out the instant we stop. There, let me open the door wider.”