Meap returns to save Phineas and Ferb from his nemesis Mitch, whose real mission is to take control of all of alien-kind, putting Meap's world in danger. The boys' "cute-tracker" leads the gang to Seattle and an adventure to save the universe. Meanwhile, Dr. Doofenshmirtz decides to revisit his former nemesis, Peter the Panda, but when Agent P shows up, Dr. Doofenshmirtz finds that he has some explaining to do.