Produced by Sankar Viswanathan, Greg Weeks, and the Online Distributed Proofreading Team at http://www.pgdp.net ASTOUNDING STORIES 20c _On Sale the First Thursday of Each Month_ W. M. CLAYTON, Publisher HARRY BATES, Editor DOUGLAS M. DOLD, Consulting Editor The Clayton Standard on a Magazine Guarantees _That_ the stories therein are clean, interesting, vivid, by leading writers of the day and purchased under conditions approved by the Authors' League of America; _That_ such magazines are manufactured in Union shops by American workmen; _That_ each newsdealer and agent is insured a fair profit; _That_ an intelligent censorship guards their advertising pages. _The other Clayton magazines are:_ ACE-HIGH MAGAZINE, RANCH ROMANCES, COWBOY STORIES, CLUES, FIVE-NOVELS MONTHLY, ALL STAR DETECTIVE STORIES, RANGELAND LOVE STORY MAGAZINE, WESTERN ADVENTURES, and WESTERN LOVE STORIES. _More than Two Million Copies Required to Supply the Monthly Demand for Clayton Magazines._ * * * * * VOL. VI, No. 2 CONTENTS MAY, 1931 COVER DESIGN H. W. WESSO _Painted in Water-Colors from a Scene in "Dark Moon._" DARK MOON CHARLES W. DIFFIN 148 _Mysterious, Dark, Out of the Unknown Deep Comes a New Satellite to Lure Three Courageous Earthlings on to Strange Adventure._ (_A Complete Novelette._) WHEN CAVERNS YAWNED CAPTAIN S. P. MEEK 198 _Only Dr. Bird's Super-Scientific Sleuthing Stands in the Way of Ivan Sarnoff's Latest Attempt at Wholesale Destruction._ THE EXILE OF TIME RAY CUMMINGS 216 _Young Lovers of Three Eras Are Swept down the Torrent of the Sinister Cripple Tugh's Frightful Vengeance._ (Part Two of a Four-Part Novel.) WHEN THE MOON TURNED GREEN HAL K. WELLS 241 _Outside His Laboratory Bruce Dixon Finds a World of Living Dead Men--and Above, in the Sky, Shines a Weird Green Moon._ THE DEATH-CLOUD NAT SCHACHNER AND ARTHUR L. ZAGAT 256 _The Epic Exploit of One Who Worked in the Dark and Alone, Behind the Enemy Lines, in the Great Last War._ THE READERS' CORNER ALL OF US 276 _A Meeting Place for Readers of Astounding Stories._ Single Copies, 20 Cents (In Canada, 25 Cents) Yearly Subscription, $2.00