"Surprise Sister" is a fan-made episode of the television series Phineas and Ferb. This episode focuses on the first appearance of Alice Fletcher, the older sister of Ferb. Alice, like the Flynn-Fletcher family, is on summer vacation and plans a surprise visit to her father and brother. Shortly after meeting, her and Candace get involved in Doofenshmirtz's latest "-inator", the "Mind-switch-inator". Phineas and Ferb spend there day trying to build something to make Alice's visit the best one ever, while Agent P foils Doofenshmirtz and his Mind-switch-inator. Once the Mind-switch-inator is destroyed by Agent P, Alice and Candace return to normal and Alice returns home to London.