When Billy and Sarah, plan to team up for the science fair, they soon find themselves embroiled in solving a mystery concerning the invasion of earth from an alien source. Billy's unusual pet mouse proves himself to be an indispensable third detective who helps them discover clues about the dangerous earth-changing element that lurks within the walls of their apartment complex. Hours count to minutes left as they unravel clues to help them attempt to bring the alien plot to a grinding halt. While the onlyweapon they have to rely on is their knowledge of science, they also learn to depend on their newfound friendship and rebuild a feeling of security within their families.Grab some adventure and read this book!