Phineas and Ferb, along with their friends, travel to a parallel dimension to rescue their pet platypus from an evil alternate version of their sister's self.
Phineas and Ferb's sister, Candace, is abducted by aliens and they embark on a mission to rescue her in outer space.
When an attack on the O.W.C.A. incapacitates the animal agents, only Agent P and his animal trainees can save the day. Carl and Monogram fend for themselves.