For a long moment Ro studied the approaching creatures. Then he gasped in surprise. The pursued was a young woman, a woman he knew. Na! The pursuer was a squat, ugly rat man, one of the vicious Oan who lived in the cliffs. Ro exclaimed his surprise, then his rage. His handsome face was grim as he searched the ground with his eyes. When he found what he sought--a round rock that would fit his palm--he stooped, and snatching up the missile, he ran forward. At great speed, he closed the gap between him and the approaching figures. He could see the rat man plainly now--his fanged, frothy mouth; furry face and twitching tail. The Oan, however, was too intent on his prey to notice Ro at first, and when he did, it was too late. For the young Martian had let fly with the round stone he carried. The Oan squealed in terror and tried to swerve from his course. The fear of one who sees approaching death was in his movements and his cry. He had seen many Oan die because of the strength and accuracy in the red men's arms. Despite his frantic contortions, the stone caught him in the side. His ribs and backbone cracked under the blow. He was dead before he struck the ground. With hardly a glance at his fallen foe, Ro ran on to meet the girl. She fell into his arms and pressed her cheek to his bare shoulder. Her dark eyes were wet with gladness. Warm tears ran down Ro's arm. * * * * * Finally Na lifted her beautiful head. She looked timidly at Ro, her face a mask of respect. The young Martian tried to be stern in meeting her gaze, as was the custom among the men of his tribe when dealing with women; but he smiled instead. "You're home," breathed Na. "I have traveled far to the north," answered Ro simply, "and seen many things. And now I have returned for you." "They must have been great things you saw," Na coaxed. "Yes, great and many. But that tale can wait. Tell me first how you came to be playing tag with the Oan." Na lowered her eyes. "I was caught in the forest below the cliffs. The Oan spied me and I ran. The chase was long and tiring. I was almost ready to drop when you appeared." "You were alone in the woods!" Ro exclaimed. "Since when do the women of our tribe travel from the cliffs alone?" "Since a long time," she answered sadly. Then she cried. And between sobs she spoke: "Many weeks ago a great noise came out of the sky. We ran to the mouths of our caves and looked out, and saw a great sphere of shining metal landing in the valley below. Many colored fire spat from one end of it. "The men of our tribe snatched up stones, and holding one in their hands and one beneath their armpits, they climbed down to battle or greet our visitors. They had surrounded the sphere and were waiting, when suddenly an entrance appeared in the metal and two men stepped out.