Produced by Greg Weeks, Stephen Blundell and the Online Distributed Proofreading Team at http://www.pgdp.net [Cover Illustration: JOHN W. CAMPBELL THE ULTIMATE WEAPON When star fights star, is chaos the best defense?] RED SUN RISING The star Mira was unpredictably variable. Sometimes it was blazing, brilliant and hot. Other times it was oddly dim, cool, shedding little warmth on its many planets. Gresth Gkae, leader of the Mirans, was seeking a better star, one to which his "people" could migrate. That star had to be steady, reliable, with a good planetary system. And in his astronomical searching, he found Sol. With hundreds of ships, each larger than whole Terrestrial spaceports, and traveling faster than the speed of light, the Mirans set out to move in to Solar regions and take over. And on Earth there was nothing which would be capable of beating off this incredible armada--until Buck Kendall stumbled upon THE ULTIMATE WEAPON. JOHN W. CAMPBELL first started writing in 1930 when his first short story, _When the Atoms Failed_, was accepted by a science-fiction magazine. At that time he was twenty years old and still a student at college. As the title of the story indicates, he was even at that time occupied with the significance of atomic energy and nuclear physics. For the next seven years, Campbell, bolstered by a scientific background that ran from childhood experiments, to study at Duke University and the Massachusetts Institute of Technology, wrote and sold science-fiction, achieving for himself an enviable reputation in the field. In 1937 he became the editor of _Astounding Stories_ magazine and applied himself at once to the task of bettering the magazine and the field of s-f writing in general. His influence on science-fiction since then has been great. Today he still remains as the editor of that magazine's evolved and redesigned successor, _Analog_. _THE ULTIMATE WEAPON_ by JOHN W. CAMPBELL ACE BOOKS, INC. 1120 Avenue of the Americas New York, N.Y. 10036 THE ULTIMATE WEAPON Copyright, 1936, by John W. Campbell Originally published as a serial in _Amazing Stories_ under the title of _Uncertainty_. All Rights Reserved _Cover by Gerald McConnell_ Printed in U.S.A. Transcriber's Note: Extensive research did not uncover any evidence that the U.S. copyright on this publication was renewed. Minor spelling and typographical errors have been corrected without note. Subscript characters are shown within {braces}. The mathematical symbol pi is shown as [pi]. [Illustration] I Patrol Cruiser "IP-T 247" circling out toward Pluto on leisurely inspection tour to visit the outpost miners there, was in no hurry at all as she loafed along. Her six-man crew was taking it very easy, and easy meant two-man watches, and low speed, to watch for the instrument panel and attend ship into the bargain.