She gave them to understand the time that was left. The sun, she showed, was long past the meridian and was on its return. The day was now reaching a close. And then, as the sun set, the great sacrifice would be made--had always been made--to insure the return of their god. * * * * * Their watches were useless, for the water had entered their cases. The two men waited what they judged was the length of a day, while Jerry tried to believe that his arm was improving. Then, putting a small supply of food in their pockets, they were ready for the attempt. Jerry saw that his gun and knife were ready at his belt, and patted a pocket where his matches were safe in their watertight container. The prospect of escape almost unnerved him. To breathe the clear air; to stand in the radiant light of the sun--he could understand now how these people made a god of the sun. He turned to Marahna. "Good-by," he said, "but not for long. We'll be back. And we'll save you, Marahna, we'll save you. Winslow will figure some way to do it.... We'll be back...." The girl was silent. She touched Jerry's arm, and shook her head slowly, doubtfully. He reached for the hand. It trembled, he felt, in his. The impulse to take the slim form within his arms, to hold her close, was strong upon him. Would he ever see her again ... would he? "Won't you say good-by, Marahna?" he asked. But she smiled, instead--a friendly smile, and encouraging. Then dropped in silence to her knees to press with both her trembling hands his hand upon her forehead. And, still in silence, she rose to vanish from the room. The men entered the narrow opening to start forward into the dark. But Jerry Foster was puzzled, puzzled and more than a trifle hurt. Marahna could at least have said good-by. She knew the word, for he had taught it to her. And she had let him--them--go.... "Oh, well," he thought, "how can I know how a princess feels--a princess of the moon? And why should I care--why should she? But...." He refused to complete the thought. He hurried instead, as best he could, to follow Winslow, fumbling ahead of him in the dark. * * * * * Jerry had used plenty of muttered invective with the massage he had given his arm, but he cursed his handicap wholeheartedly at the end of some several hours. They were standing, he and Winslow, in a dark tunnel. They had climbed and clawed their way through the absolute dark, over broken fragments, through narrow apertures, down and up, and up again through a tortuous, winding course. And now they had reached the end. They had found the source of the fresh air, had come within reaching distance, it seemed, of sunlight and all that their freedom might mean. And they had come, too, to a precipitous rock wall.