Bart accidentally gets Principal Skinner fired after he brings Santa's Little Helper to school for show and tell. Bart feels guilty for what he did, and befriends Skinner. Meanwhile, Ned Flanders is hired as principal and the school goes to pot. Bart decides that while he enjoys having Skinner as a friend, he needs him as an enemy, but discovers that he returned to the Army to be a sergeant. Bart convinces Skinner to return and they get Flanders fired so that Skinner can get his old job back.