Undercover Carl, Hip Hip Parade

When the boys build an Anti-Gravity Fun Launcher, Carl accidentally intercepts their plans and assumes they are working for Dr. Doofenshmirtz, so he is sent undercover to figure out what they are doing. Meanwhile, Perry tries to find a lost agent, and Dr. Doofenshmirtz also acquires the blueprints to help with a parking issue on his street.
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.