Produced by Greg Weeks, Barbara Tozier and the Online Distributed Proofreading Team at https://www.pgdp.net This etext was produced from Astounding Stories September 1931. Extensive research did not uncover any evidence that the U.S. copyright on this publication was renewed. [Illustration: The tip sprayed a web around his body.] Devil Crystals of Arret _By Hal K. Wells_ Facing a six-hour deadline of death, young Larry raids a hostile world of rat-men and tinkling Devil Crystals. Benjamin Marlowe and his young assistant, Larry Powell, opened the door of the Marlowe laboratory, then stopped aghast at the sight which greeted their startled eyes. There on the central floor-plate directly in the focus of the big atomic projector stood the slender figure of Joan Marlowe, old Benjamin Marlowe's niece and Larry Powell's fiancee. The girl had apparently only been awaiting their return to the laboratory for around her gray laboratory smock was already fastened one of their Silver Belts, and a cord was already in place running from her wrist to the main switch of the projection mechanism. Joan's clear blue eyes sparkled with the thrill of high adventure as she swiftly raised a slender hand in a gesture of warning to the two men. "Don't try to stop me," she warned quietly. "I can jerk the switch and be in Arret, before you've taken two steps. I'm going to Arret, anyway. I was only waiting for you to return to the laboratory so I'd be sure of having you here to bring me back to Earth again before I have time to get into any serious trouble over there." "But, Joan," Benjamin Marlowe protested, "this is sheer madness! No one can possibly guess what terrible conditions you may confront in Arret. We've never dared to send a human being across the atomic barrier yet!" "We've sent all kinds of animals across, though," Joan retorted calmly, "and as long as we recalled them within the twelve-hour limit they always came back alive and unhurt. There's no reason why a human being should not be able to make the round trip just as safely. Ever since our Silver Belts first came back with the weird plant and mineral fragments which proved that there really is such a place as Arret, I've been wild to see with my own eyes the incredible things that must exist there." Joan waved her hand in gay farewell. "Good-by, Uncle Ben and Larry! I know that you'll drag me back just as quickly as you can possibly dash over to the recall switch, but I'll at least have had a few precious seconds of sightseeing as Earth's first human visitor to Arret!" * * * * * Larry Powell was already sprinting for the mechanism as Joan jerked the cord that ran to the switch, but he was barely half-way across the intervening space when the big atomic projector flared forth in a brilliant gush of roseate flame.