Candace and Suzy try to get Phineas and Ferb to bust themselves, the boys build a replica of Niagara Falls so they can ride a barrel over it, Doofenshmirtz builds a device to increase his carbon footprint.

Phineas and Ferb decide to help build floats for all the neighborhood kids in the yearly "Tri-State Area Unification Day" parade, but a family grudge leads Buford and his family to try and wreak havoc on the parade.