An alien named Meap crashes in Phineas and Ferb's backyard. The boys repair his ship as he runs off after Candace. When Phineas, Ferb, and Isabella set off searching for Meap, they are captured by his nemesis, Mitch, and it's up to Candace and Meap to save them. At the same time, Doofenshmirtz attempts to find a long-lost companion of his.