After dismissing the idea of taking Simpson family home videos and a geode, Bart brings Santa's Little Helper to school for show and tell. Even though his show-and-tell presentation is well received by the class, the dog escapes into the school air ducts to follow the food scent coming from the kitchen and is spotted by Ralph Wiggum. Groundskeeper Willie is sent after the dog and catches it, but he chooses the wrong vent to exit and the fire department is called in to rescue him. As the firemen are attempting to rescue Willie, an outraged Superintendent Chalmers appears and fires Principal Skinner, much to Bart's shock.
Chalmers hires Ned Flanders as the new principal of Springfield Elementary School, but when Flanders is hesitant to discipline the children, they run amok, and the school becomes a mad house. Meanwhile, Bart befriends the now jobless Skinner, as they laugh about anecdotes of Flanders's failure that Bart relates. Feeling lonely, Skinner eventually decides to re-enlist in the United States Army.
Instead of rejoicing in the discipline-less school, Bart feels guilty about causing Skinner's dismissal. In an effort to get Skinner his job back, Bart attempts to expose Flanders' poor leadership to Chalmers. Despite the state of chaos at the school, Chalmers is not concerned. However, upon hearing Flanders utter a brief mention of God over the intercom, Chalmers immediately fires Flanders for reciting a school prayer. Skinner is soon re-hired as principal. Bart and Skinner share an amicable chat about their typically antagonistic relationship, then affectionately pat each other on the back. However, as they turn from each other, it is revealed Bart has taped a "Kick Me" sign on Skinner's back, and Skinner has taped a "Teach Me" sign on Bart. The two chuckle to themselves as they walk away.