Now, however, most of the yellow mist had disappeared, and that was all Kirby had been waiting for. With a growling shout, he tore out from behind his boulder, his Luger ready. Naida's captors were in full retreat, and other pairs of men were snatching up other girls and hopping after them. Toward Naida Kirby ran madly but not blindly. "Naida! Naida!" he bellowed. He got in two strides for every one the apes made. "Naida!" he shouted, and at last saw her look at him. Her face was pallid with loathing and terror. As her glimmering dark eyes met his, they flashed a plea which made his heart thrash against his lungs. With a final roar of encouragement Kirby closed in on the hair-covered men, and fired instantly a shot which caught one full in the heart. The creature wavered on its legs, looked at the unexpected enemy with dismayed, swinish little red eyes, and relaxing his hold upon Naida, dropped without making a sound. After that-- But suddenly Kirby found himself unable to comprehend fully the other terrific results of his intervention. Before the echoes of his shot died, there came to him the rumble of what seemed to be tons of falling rock. In the bright air a slight mist was precipitated. To all of which was added the effect upon the ape-men of fear of a weapon and a type of fighter utterly new to them. Kirby had fired believing that he would have to fight other ape-men when the first fell. But not so. Instead of that-- * * * * * He blinked rapidly as he took in the scene. Naida had been released. Lying on the sand beside the dead ape-man, she was looking up at him in stupefied wonder. And her other captor, instead of remaining to fight, had clapped shaggy hands over his ears, and was leaping headlong for the protection of the jungle! Moreover, the soprano cries of the girls and the deep howls of the men were rising everywhere, and everywhere the ape-men were dropping their captives and plunging away after their leader. "Huh," Kirby muttered aloud, and wondered what the citizens of Kansas would have to say about _this_. Naida looked at the dead and bleeding ape-man and shuddered, and then at the score or so of others brought down by the puff balls. Then she looked up at Kirby, raised her arms for his support, and smiled up into his brown face. Kirby forgot Kansas, lifted her, warm and alive, radiantly beautiful, in his arms. "Our friends the enemies," she whispered as she remained for a second in his embrace and then drew away, "will attack no more this day--thanks to you." There was no possible need for another shot, Kirby saw. In terrified silence, the first of the apes had already floundered behind the prickly pear and aloe bushes, and the last stragglers were using all the power in their legs to catch up. On the beach, Naida's followers were picking themselves up, and already a few of them had burst into ringing laughter.