Each day, two kindhearted suburban stepbrothers on summer vacation embark on some grand new project, which annoys their controlling sister, Candace, who tries to bust them. Meanwhile, their pet platypus plots against evil Dr. Doofenshmirtz.

Perry’s worst fear comes true when Phineas and Ferb finds out that he is in fact Secret Agent P, but that soon pales in comparison during a trip to the 2nd dimension where Perry finds out that Dr. Doofenshmirtz is truly evil and successful.