"What's the matter?" asked Davis quickly. "Look out the window," said the pilot in a tone indicating that he could not believe his eyes. Davis looked, and his month dropped partly open. Before them the white patch of light had turned golden and then yellow. A bank of clouds lay before them, behind which the sun was evidently hidden. That had not caused Davis' exclamation, however. He was not amazed at anything he saw, but at the lack of something he did not see--the ocean. The cloud bank was illuminated by the sun. It covered half of the sky before them, _and below them_! There was no ocean below them. There was no land below them. Above, the rapidly graying sky could be seen. Below them was rapidly graving sky! There was no horizon, there was no land, there was no sea. There was only sky. They seemed to be alone in an illimitable firmament, a derelict in open space, adrift in some unthinkable ether in which there was no landing space or any solid thing except themselves. Above them and below them, before them and behind them, on their right side and their left side was sky, and nothing but sky. There was not one bit of solid matter visible on either side, ahead or behind, up or down. It was as if they had gone aloft, and while they flew the earth had been destroyed. Only the incredibility of such a catastrophe kept them from believing it instantly. "Teddy," said Davis in a moment or two, trying to jest, though his voice was shaking, "you're our tame scientist. What's happened to our well-beloved earth? Has it gone off and left us in the lurch? Have we flown off into space?" Gerrod was looking with all his eyes. He looked down into a blue bowl that was the exact counterpart of the dome above. "Which way is down?" he asked quietly. "Is it that way, or that way?" He pointed over his head and at his feet. "Are we flying right side up, or upside down, or what?" The plane banked sharply and side-slipped for a moment before it recovered. "Steady!" said Davis to the man at the controls. "Steady----" The machine banked again, then shot upward, stalled, and slipped on again. "Straighten out!" said Davis sharply. "Up with the joy stick!" "I don't know what's what," said the white-faced pilot desperately, obeying as he spoke. "Great God! What's happening now?" The plane seemed to be standing on its tail, and the three men standing in the car slid toward the rear. Davis seized a seat and clambered toward the controls. As he made his way toward the instruments the plane seemed to go mad. It twisted, turned, stood upon its head and darted forward, and then seemed to be wallowing in the air. Davis seized the controls, and with his eye solely on the inclinometer worked madly for a moment. The plane stopped its antics and drove on steadily. "It's like driving in a fog," he said over his shoulder. "All right back there now?" "Yes." Gerrod was answering. "What happened?"