As it has come to summer vacation, mischievous Phineas and his quiet stepbrother Ferb decide to make the best of each and every day off school together. Those two little geniuses always come up with incredible inventions, while their elder teenage sister tries every possible attempt to have the boys busted, but never succeeds. This animated also features Perry, the family's pet platypus who leads a double life as "Agent P" and his fight against a devil scientist known as Dr. Doofenshmirtz.