NEXT DOOR, NEXT WORLD By ROBERT DONALD LOCKE Almost any phenomenon can be used—or act—for good or ill. Mutation usually brings ill—but it also brings greatness. Change can go any direction. Illustrated by Douglas ungrily, the cradled vessel's great steel nose pointed up to the distant stars. She was the Cosmos XII, newest and sleekest of the Space Service's rapidly-expanding wing of interstellar scout ships, and she was now ready for operational work. ungrily Major Lance Cooper, a big man with space-tanned features, stood in the shadow of the control bunker and watched the swarm of ground crewmen working at last-minute speed atop the loading tower. Inside him burned a hunger, too. Hunger, and another emotion—pride. The pride swelled Lance's open-collared khaki shirt, as he envisioned himself at the ship's controls within a few minutes. Finally, after long years of study, sweat and dedication, he'd made it to the Big League. No more jockeying those tubby old rocket-pots to Luna! From here on, he was going to see, taste, feel what the universe was like way, way out—in Deep Space. The Cosmos XII, like her earlier sisters, was designed to plow through that shuddery nowhere the cookbooks identified as "hyperspace." Lance's glance shifted upward, scanning the velvet backdrop of frosty white points of light against which the slender, silverish, almost wingless form stood framed. More stars than a man could visit in a lifetime! And some already within grasp! His exultant feeling grew, and Lance kept his head tilted backward. Alpha Centauri, the most popular target, was not visible at this latitude; and Barnard's star, besides being far too faint, lay on the other side of the sun. But there shone Sirius, just as bright as it had glittered for the Greeks, and frosty Procyon, a little to the north. Both orbs twinkled and beckoned, evoking strange and demanding dreams! One day, Man would be able to make landings. Teams of scientists outfitted to the eyebrows and trained to cope with any environment or emergency, would explore unknown jungles, llanos, steppes; tramp up and down fertile vales and hills under blue-hot alien suns. Perhaps, they might even contact native species boasting human intelligence: mammalian hunters and fishers,