Phineas and Ferb the Movie: Across the 2nd Dimension is a 2011 American animated science fantasy action-adventure comedy-drama television film based on the American animated TV series Phineas and Ferb. The film premiered on August 5, 2011 in the United States. It was first announced by Jeff "Swampy" Marsh during a January 2010 interview with the Daily Telegraph. The events of the film take place during the third season of Phineas and Ferb. It is the first feature-length film of the Phineas and Ferb series, and the third animated Disney Channel Original Movie, following Kim Possible Movie: So the Drama and The Proud Family Movie.

Plot

Phineas and Ferb start another summer day playing with Perry and are inspired by him to create an enormous shuttlecock to play platypult (platypus + catapult) badminton. Perry enters his secret lair and is warned by Major Monogram that he has had some close calls with the Flynn-Fletchers almost seeing him entering his lair. He reminds Perry that if his cover is blown, he will have to be relocated away from the Flynn-Fletchers, and also reveals that Perry has an auto-scan replication device in his hat, which he has used to scan and replicate all of Doofenshmirtz's "inators" to determine whether Doofenshmirtz is getting smarter.