Phineas Flynn and his stepbrother, Ferb Fletcher, set out to conquer boredom and make every day of their 104-day summer vacation count. However their older sister, Candace, who gets frantic at her brothers' extraordinary adventures, makes it her life's work to tattle on them to Mom and Dad - but somehow she's never quite able to prove what the boys have done. On every adventure Phineas and Ferb are accompanied by their pet platypus, Perry, who seems to be a quiet and simple family pet, but no one, including Phineas and Ferb, knows that Perry has a secret life as suave Agent P, deftly battling the evil Dr. Doofenshmirtz to save the world!