An alien race known as the Boov, led by the self-proclaimed superior Captain Smek, invades Earth to hide from their mortal enemy and to make it their new home. The Boov believe they're doing humans a favor by relocating them to a remote desert planet and taking over in an oddly bureaucratic, but peaceful, manner. During the invasion, a well-meaning but clumsy Boov named Oh stands out for causing accidents. When he sends an invite to his housewarming party that mistakenly gets sent to the entire galaxy, it reveals their location to their enemy. Fearing the consequences, Oh becomes a fugitive within Boov society.

Meanwhile, a plucky young girl named Tip manages to avoid being captured and subsequently separated from her mother during the human relocation. Alone except for her pet cat, she's determined to find her mother. By chance, Tip and Oh meet, and after initial mistrust, they realize they can help each other. Oh agrees to assist Tip in her search for her mother, using technology that only he can manipulate as a Boov. As they embark on a road trip across a transformed and alien-run Earth, they begin to challenge their perceptions of each other, experiencing a series of comic adventures and forming an unlikely friendship. Their journey is filled with moments that are both heartwarming and humorous as they learn about the true meaning of home.