A New York Times Bestselling Author A Newbery Award-Winning Author A Guardian Prize for Children's Fiction-Winning Author A Junior Library Guild Selection Nathan never understood what was "fun" about secrets, probably because he's always had to keep a very big one. Although he appears to be a typical sixth-grader (with parents, homework, and a best friend, Victor), Nathan learned at an early age that his family is from another planet. Now, their time on Earth may be coming to an end. Nathan, his parents, and nine other families are part of an experiment that suddenly seems to be going wrong. Some of the experimenters, including Nathan's first crush, Izzy, are disappearing without a word. After his family is called back to the mothership, Nathan begins to question everything he's been taught to believe about who he is and why he's on Earth.