Alex and Christina’s parents were former astronauts who were in charge of sending the space shuttle Andromeda to an orbit around the moon where it is intended to launch a nuclear-powered spacecraft to the outer reaches of the solar system. But when the mischievous twins turned thirteen, they beginning wondering if their parents were really their parents when they discovered they have the ability to do things that none of their friends can do. At first they used their powers for fun, for playing tricks on each other, doing their homework quickly, and helping out friends. It took them a while to learn that they had been given these abilities for a serious purpose, but by then things had gotten out of control. A murderous, shape-shifting creature has discovered who they really are and is manipulating them to prevent them from stopping what it is planning to do. The biggest mistake the alien creature made was to underestimate the Brenner twins.