
Phineas Flynn and his stepbrother, Ferb Fletcher, are determined to make every day of their summer vacation fun. They try building a full-scale roller coaster, becoming musicians, building a backyard beach, and traveling back in time to meet dinosaurs. Their family pet, Perry the Platypus, doubles as a secret agent and battles evil. Meanwhile, older sister Candace is tattling on them to Mom and Dad, though she can never seem to catch them in the act.

The boys build a zoetrope that goes on an adventure of its own; the kids build a bookcase that gets attacked by an army of Doof-plants.

While Buford is sick, Baljeet makes him watch an episode of his favorite show, "Space Adventure!"; Isabella works with Doof to bake a giant pastry to impress foreign emissaries.

Doof gathers energy from people exercising while the kids pilot a boat that surfs concrete; Candace and Jeremy make a Perry documentary as the kids play an extreme game of croquet.

The Flynn-Fletchers take a cruise; Doof steals shrunken goods; Isabella struggles to lead the Fireside Girls on her own, while Doof renews his evil business license.