Issued monthly by The Clayton Magazines, Inc., 80 Lafayette Street, New York, N. Y. W. M. Clayton, President; Francis P. Pace, Secretary. Entered as second-class matter December 7, 1929, at the Post Office at New York, N. Y., under Act of March 3, 1879. Title registered as a Trade Mark in the U. S. Patent Office. Member Newsstand Group. For advertising rates address The Newsstand Group, Inc., 80 Lafayette Street, New York; or The Wrigley Bldg., Chicago. * * * * * The Doom from Planet 4 _By Jack Williamson_ [Illustration: _For long seconds he was plunging down through space._] [Sidenote: A ray of fire, green, mysterious, stabs through the night to Dan on his ship. It leads him to an island of unearthly peril.] "S O S. S O S. S O S." Three short, three long, three short, the flashes winked from the dark headland. Dan McNally, master and owner of the small and ancient trading schooner, _Virginia_, caught the feeble flickering light from the island as he strode across the fore-deck. He stopped, stared at the looming black line of land beneath the tropical stars. Again light flashed from a point of rock far above the dim white line of phosphorescent surf, spelling out the signal of distress. "Somebody bane callin' with a flashlight, I t'ank," the big Swede, Larsen, rumbled from the wheel. Dan thought suddenly of a reply. He rushed into the charthouse, to return in a moment with a lighted lantern and a copy of the _Nautical Almanac_ which would serve to hide the flame between flashes. He flashed an answer. Again the pale light flickered from the dark mass of land, spelling words out rather slowly, as if the sender were uncertain in his knowledge of Morse. Surprised as Dan had been by the signal from an island marked on the charts as uninhabited, he was astonished at the message that now came to him. "You are in terrible danger," he read in the flashes. "Dreadful thing here. Hurry away. Radio for warships. I am--" The winking light suddenly went out. Dan strained his eyes to watch the point where it had been, and a few seconds later he saw a curious thing. A darting, stabbing lance of green fire flashed out across the barren, rocky cliff, lighting it fleetingly with pale green radiance. It leapt out and was gone in an instant, leaving the shoulder of the island dark as before. Dan watched for long minutes, but he saw nothing more brilliant than the pale gleam of phosphorescence where the waves dashed against the sheer granite wall of the island. "What you t'ank?" Larsen broke in upon him. * * * * * Dan started, then answered slowly. "I don't know. First I thought there must be a lunatic at large. But that green light! I didn't like it."