Again the walls glowed as they had before, but far off in the distance. Chet saw them grow luminous while he seemed hung motionless in space. Then once more they drew away from him; once more he knew he was falling away from that light--plunging again into the depths he had traversed. And now, despite the oxygen that came to him uninterruptedly, he found his head swimming. The limit of human endurance had been reached. Desperately he tried to bring his reason to bear upon this miracle that had happened. He had not struck; instead of falling to his death he had cushioned against something; he was falling again where, not far away, another metal-clad figure hung limply in air and fell as he fell. And with that knowledge the whirling turmoil within his brain ended in a blood-red flashing that went finally to merciful darkness.... * * * * * That darkness still wrapped him thickly about when he regained consciousness--a darkness saved from utter black only by a faint luminosity that seemed to penetrate and be part of the air about him. Still hardly more than half-conscious, lying, it seemed, on a soft bed where he was weightless, he stirred and flung out one arm. From his fingertips he saw whirls of violet light sweep out and away, as vortices might have been set in motion by a swimmer in a more liquid medium. Fascinated, failing utterly to comprehend where he was, he moved his hands deliberately, swept one arm from side to side--and a number of luminous whirlpools went spinning out into space. And then he remembered. He remembered the terrific fall that miraculously brought him back to a place of light like that where his fall had begun. He remembered beginning the second fall; and, while he still could not know what it meant, he knew that he must have been unconscious for hours. And, with that, his thoughts came back to the girl. For the first time he found leisure to give mental voice to his wonderment. The mystery of it all!--of her presence here on the Moon! Again he was overwhelmed with the wonder of his surprising discovery. It was nearly beyond belief; almost he doubted the reality of what his own eyes had seen. * * * * * But there was no doubting his own presence here in this strange place. The unreality of it--the strangeness of his own sensations--were borne in upon him. Where was he? he asked. What was this soft cushion upon which he rested so lightly? He tried to sit up and found that he merely twisted his body and set other eddies of light into motion.