The Springfield gay pride parade passes by the Simpsons' home, during which Santa's Little Helper flirts with one of the gay dogs. Uncomfortable, Homer drags his family to the Springfield Googolplex to see a movie called "Shenani-Goats" starring Tim Allen and rated PG-13 for brief rudeness and appearances by Garry Shandling. Homer grows impatient at the number of short films, previews (including one for a family movie called Soccer Mummy starring Ed O'Neill), on-screen trivia games, and public service announcements preceding the film. He jumps up in front of the screen chanting, "Stop the madness! Start the movie!" The angry ushers then chase Homer out of the cinema, wielding oversized Kit Kat bars. While running without looking where he is going, Homer collides with the fist of a large metal statue of boxer Drederick Tatum.
At the Springfield General Hospital, Dr. Hibbert wires Homer's broken jaw shut, saying that he will not be able to speak or eat solid food for a while. Not being able to talk, Homer starts to listen to his family, which pleases them, especially Marge. She decides that, since Homer is so well-behaved, they can risk going to the Springfield annual formal event at the Country Club. The next day, the jaw wires come off. Homer and Marge appear on a chat show called "Afternoon Yak" to discuss how Homer became a changed man. During the show, Marge, with the support of the hosts, pleads with Homer to stop his "weckless ways" and stay well behaved. Despite the temptation of the upcoming demolition derby, Homer decides not to do it for Marge's sake.
Five weeks after Homer made his pledge to behave, Marge realizes that she is bored by all the sudden peace and quiet. The demolition derby form flies into her hand, and she decides to give it a try. When she leaves, Homer wakes up and finds Marge is gone and so is the demolition derby form, so he heads off to the derby with the kids to stop her. Although Marge initially enjoys the demolition derby, things soon get too dangerous for her. Homer has no idea how to save her, as he has given up being reckless. Bart comes up with an idea and calls for a beer can from a vendor. Homer then drinks the beer and rescues Marge (in a style similar to Popeye), who makes him promise not to make her the live wire in the family.