During Christmas vacation, Phineas and Ferb's quest to show gratitude to Santa during Christmas may be doomed for failure, when Dr. Doofenshmirtz uses an invention that puts the entire town of Danville on Santa's naughty list.

In this special episode, Agent P leads a rather inept team of trainees, including Dr. Doofenshmirtz, to try to stop an evil mastermind from taking over the O.W.C.A. Meanwhile, the Bug Trio continue their frivolous attempts at human communication.