"Lots of planets up there," he continued. "In other solar systems. Lots of different kinds of beings. I suppose some of those races, on planets of the older stars, have really grown up mentally and scientifically, till they know all about time and space and dimensions and energy, and how to handle and conquer them. And I suppose that somehow they keep careful watch across the awful distance because they've learned by experience that it may be safer. It's not just to save the necks of lesser beings but to guard themselves, too. I was messing around with something pretty big, Ellen. You can't tell how far a danger may sometimes go. A whole universe may be thrown into chaos--" Sam's fists were clenching and unclenching absently. It was better for science to develop gradually, with a race. And even then there would sometimes be mistakes. Atlantis. Mu. The asteroids. Maybe some of the novae-- "We'd better get back into town, Sam," Ellen offered practically. "There may be damage done there--with all that's been happening. We'd better see." A chuckle found its way through Sam Conway's awe. "Yeah," he said. "Like your car. I see the headlights have gone out. Good thing it's a diesel, with no electrical ignition to blow, and with a cartridge starter on the motor." But Sam was too grateful over the miraculous escape from final tragedy he'd just witnessed, to worry much about damage suits over ruined electrical equipment. And he was very grateful for Ellen, too. He might fly out to Mars some time again, or even farther. But when he touched the girl's warm shoulder he knew that he was truly home at last.