A young inventor gets in and out of trouble in an out-of-this-world summer adventure.Their already small house becomes even smaller when Ethan's brothers return from college, making for four boys, two parents, a guinea pig, and a lack of space for Ethan's projects. Luckily, an abandoned factory offers him a place to tinker while avoiding his ex–best friend, Kareem, who has seemingly teamed up with neighborhood bullies in a frustrating act of betrayal. New arrival Juan Carlos is having a hard time settling in, but soon he and Ethan build a strong bond while outrunning those bullies and clumsily making first contact with an alien. When Kareem returns to the fold, explaining that his mood changes were fallout from his parents' messy divorce, the three sixth graders make for an impressively empathetic friend group of Black and brown boys who are transparent about their fears while working together to help the extraterrestrial visitor they lovingly name Cheese. Getting Cheese home, however, will require navigating the police-who understandably don't have the best reputation in this community-and the mysterious agents they're working with who are obvious threats to Cheese. Flashy science-fiction elements are paired with authentically kidlike attention to social realities as Ethan reflects on the value of connections in the face of confusing threats. Although all is resolved in a sort of anticlimactic and idyllic hurry, the boys find happy endings that readers will root for.An inventive story with a lot of heart. (Science fiction. 8-12)