The guys help their dad unearth a missing piece of Danville history; Doofenshmirtz tries to make himself younger to win a children's film festival.

Candace finds it difficult to bust Phineas and Ferb when her brothers build nanobots that can assemble into any object they can imagine. Meanwhile, Dr. Doofenshmirtz has jury duty, so Norm takes over the day's evil scheme -- to destroy Danville by using weapons.