Phil recruits Jase, Jep, Si, and John Luke for his campaign to wipe out the latest beaver infestation on the family land. They have some dynamite, but no safety fuses, and must resort to Si's homemade napalm in order to destroy the main beaver dam. Willie decides to join Bella in her introductory karate class, but his less-than-serious attitude quickly gets on the instructor's nerves and leads to painful embarrassment.