And Mac, while he laughed, had seemed half to believe it. Said the old cuss was so sincere, and he had nothing to sell. And--there was the ship! It never got there without being flown in, that was a cinch. And there wasn't a propellor on it nor a place for one--just open ports where a blast came out, or so the inventor said. Captain Blake swung his ship on another slanting line and continued to comb the country for such marks as McGuire had seen. And one moment he told himself he was a fool to be on any such hunt, while the next thought would remind him that Mac had believed. And Mac had a level head, and he had radioed from Venus! There was the thing that made anything seem possible. Mac had got a message through, across that space, and the enemy had ships that could do it. Why not this one? And always his eyes were searching, searching, for a level rocky expanse and a tree-filled valley beyond, with something, it might be, shining there, unless the inventor had camouflaged it more carefully now. * * * * * It was later on the same day when Captain Blake's blocky figure climbed over the side of the cockpit. Tired? Yes! But who could think of cramped limbs and weary muscles when his plane was resting on a broad, level expanse of rock in the high Sierras and a sharp-cut valley showed thick with pines beyond. He could see the corner only of a rough log shack that protruded. Blake scrambled over a natural rampart of broken stone and went swiftly toward the cabin. But he stopped abruptly at the sound of a harsh voice. "Stop where you are," the voice ordered, "and stick up your hands! Then turn around and get back as fast as you can to that plane of yours." There was a glint of sunlight on a rifle barrel in the window of the cabin. Captain Blake stopped, but he did not turn. "Are you Mr. Winslow?" he asked. "That's nothing to you! Get out! Quick!" Blake was thinking fast. Here was the man, without doubt--and he was hostile as an Apache; the man behind that harsh voice meant business. How could he reach him? The inspiration came at once. McGuire was the key. "If you're Winslow," he called in a steady voice, "you don't want me to go away; you want to talk with me. There's a young friend of yours in a bad jam. You are the only one who can help." "I haven't any friends," said the rasping voice: "I don't want any! Get out!" "You had one," said the captain, "whether you wanted him or not. He believed in you--like the other young chap who went with you to the moon." * * * * * There was an audible gasp of dismay from the window beyond, and the barrel of the rifle made trembling flickerings in the sun. "You mean the flyer?" asked the voice, and it seemed to have lost its harsher note. "The pleasant young fellow?"