With the day off from school, Bart uses some industrial adhesive to glue novelty items to his face. As a result Marge must take him to the doctor to have the items removed, preventing Lisa from attending an exhibit at the museum. Lisa asks her if she can take the bus downtown. Marge tells her no, so Lisa uses her brain to outwit her father into letting her take her first solo bus trip. Despite her brain, Lisa gets on the #22A bus instead of the #22. Lenny and Carl make Homer realize that he should not have allowed her to go by herself, so he leaves work in search of her. Meanwhile Lisa has ended up somewhere outside of town. Homer gets into a cherry-picker to survey the town and he sees her, just before he almost gets killed. He tells her about the wonders of taking stupid risks and to demonstrate his point, they break into the museum after it closes. While there, they make an anthropological discovery.

After Bobby eats too much sugar one morning, he is mistakenly diagnosed with attention deficit disorder. Feeling guilty about not spending enough time with her son, Peggy decides to give up teaching and be a stay-at-home mother, a decision Hank fully approves of. But Peggy is so bored at home that she starts taking guitar lessons, and composes a symbolic song about a turtle trapped in her shell. Meanwhile, Bobby takes pills for his ADD, and Luanne becomes convinced that she caught ADD from Bobby.

Mulder and Scully are instructed by Skinner to assess the threat at a telemarketing center in Illinois. A similar incident has happened before and this time a manifesto was sent to a Chicago radio station with claims of a paranormal nature at the center. Feeling that the case is a waste of time, Mulder tells Scully to stay behind while he plays the good Bureau kicking boy. However, Mulder soon realizes that the case is actually an X-File.