Mallory Moss knows how the world works. After meeting the cool girl, Reagan, she finally has a best friend, and Reagan makes Mallory feel like she belongs, like she can fit in this infinite universe, as long as she follows Reagan’s simple rules: wear the right clothes, control your image, know your place. But when Jennifer Chan moves into the house across the street, those rules don’t feel quite so simple anymore. Because Jennifer is different. She doesn’t seem to care about the laws of middle school, or the laws of the universe. She’s willing to embrace the strange, the unknown, the extraterrestrial. She believes in aliens and she thinks she can find them. Then Jennifer goes missing. The adults say she ran away. Using clues in Jennifer’s journals about alien encounters, Mallory attempts to find her. But the closer she gets, the more Mallory has to confront why Jennifer might have run and face the truth within herself.