Dixon found the prospector's horse and burro sprawled on the ground half a dozen yards away, both animals frozen in the same baffling condition of living death. Dixon's brain reeled as he tried to fathom the incredible calamity that had apparently overwhelmed the world while he had been hidden away in his subterranean laboratory. Then a new and terrible thought assailed him. If the grim effect of the baleful green rays was universal in its extent, what then of old Emil Crawford and his niece, Ruth Lawton? Crawford, an inventor like Dixon, had his laboratory in a valley some five miles away. An abrupt chill went over Dixon's heart at the thought of Ruth Lawton's vivid Titian-haired beauty being forever stilled in the grip of that eery living death. He and Ruth had loved each other ever since they had first met. Dixon broke into a run as he headed for a nearby ridge that looked out over the valley. His pulse hammered with unusual violence as he scrambled up the steep incline, and his muscles seemed to be tiring with strange rapidity. He had a vague feeling that the rays of that malignant green moon were beating directly into his brain, clouding his thoughts and draining his physical strength. Gaining the crest of the ridge, he stopped aghast as he looked down the valley toward Emil Crawford's place. Near the site of Crawford's laboratory home was an unearthly pyrotechnic display such as Dixon had never seen before. An area several hundred yards in diameter seemed one vivid welter of pulsing colors, with flashing lances of every hue crisscrossing in and through a great central cloud of ever-changing opalescence like a fiery aurora borealis gone mad. * * * * * Dixon fought back the ever-increasing lethargy that was benumbing his brain, and groped dazedly for a key to this new riddle. Was it some weird and colossal experiment of Emil Crawford's that was causing the green rays of death from a transformed moon, an experiment the earthly base of which was amid the seething play of blazing colors down there in the valley? The theory seemed hardly a plausible one. As far as Dixon knew, Crawford's work had been confined almost entirely to a form of radio-propelled projectile for use in war-time against marauding planes. Dixon shook his head forcibly in a vain effort to clear the stupor that was sweeping over him. It was strange how the vivid rays of that malevolent green moon seemed to sear insidiously into one's brain, stifling thought as a swamp fog stifles the sunlight. Then Dixon suddenly froze into stark immobility, staring with startled eyes at the base of a rocky crag thirty yards away. Something was lurking there in the green-black shadows--a great sprawling black shape of abysmal horror, with a single flaming opalescent eye fixed unwinkingly upon Dixon.