Opening Credits: Blackboard joke: None Couch gag: The family runs into the living room and they are startled to see that the couch is missing.
Act One: Without any supervision, the students in Lisa's class are having fun being loud and rowdy, when Principal Skinner escorts a sobbing Miss Hoover into the classroom. Miss Hoover announces that she has Lyme disease and that Principal Skinner will be taking over until the substitute teacher arrives. Meanwhile, one floor above in Bart's class, Bart is busy grossing out his classmates during show and tell, by showing the home video of when his cat Snowball II was born.
Down in Lisa's class, Skinner is busy teaching the students, when a man dressed as a cowboy bursts into the room firing off revolver type cap guns. Skinner ducks for cover and the man apologizes, explaining that he is the substitute teacher and that using the fake guns is his way of getting the students attention. The new teacher introduces himself as a cowboy from 1830 and tells the students that anyone who can spot three things wrong with his costume will win his cowboy hat. Lisa guesses correctly and seems to be smitten with the new teacher as he gives her his hat. He finally introduces himself as Mr. Bergstrom and his friendly, joking manner are a hit with the students, especially Lisa. Meanwhile in Bart's class, Mrs. Krabappel announces the upcoming election for 4th grade class president, and suggests that the class nominate Martin Prince to be a candidate.
Back in Lisa's class, Lisa is enamored with Mr. Bergstrom; she wears his cowboy hat as he walks around the room playing his guitar and singing a cowboy song. The students pass a note around the class, on which is a funny drawing of Mr. Bergstrom, labeled, "The Singing Dork." The note makes its way to Lisa and she is mortified when Mr. Bergstrom catches her with it. However, Lisa is relieved, when Mr. Bergstrom also thinks the drawing is funny and is not insulted. Soon after, the class passes around a note depicting her as, "The Singing Dorkette." Meanwhile, in Bart's class, Sherri and Terri nominate Bart to run for class president. As Bart cracks a few jokes for the class, Mrs. Krabappel hurriedly writes a fake note for Bart to take to the office to keep him busy; she fears that Bart's antics and popularity will win him the election.
In Lisa's class, all the students are gathered around as Mr. Bergstrom reads Charlotte's Web, and cries as he reads the ending. Later on Mr. Bergstrom goes around the room and encourages everyone to show off a hidden talent. When he makes it to Lisa and sees her saxophone case, he asks her to play a little. A nervous Lisa doesn't want to, and Mr. Bergstrom lets her off the hook, telling her that she owes him something special later. After class, Lisa decides to stick around to talk to Mr. Bergstrom. When she heads back to the classroom, she witnesses Mrs. Krabappel trying to seduce Mr. Bergstrom in a scene that parodies The Graduate. Lisa hides out in the hallway and silently cheers as Mr. Bergstrom turns down the frisky Mrs. Krabappel. Later, Lisa stands out in the schoolyard playing her saxophone; Mr. Bergstrom comes to the window, looks down with a smile and applauds her talent.
Act Two: As they do laundry at home in the basement, Lisa talks Marge's ear off about Mr. Bergstrom and all of his nuances. Lisa follows Marge through the kitchen and tells her that Mr. Bergstrom cried at the end of Charlotte's Web. Homer and Bart overhear this and Lisa is not amused as they laugh at Mr. Bergstrom's expense. Later, in Lisa's class, as the students are released for lunch, Mr. Bergstrom asks Lisa to stay for a minute so he can talk to her. He confronts her about the neatness and constant good work she does on her homework and asks her if her father helps her with it. She quickly and very convincingly explains that Homer does not help with her homework.
In Bart's class, the two presidential candidates, Martin and Bart, hold a debate. Martin cites that the classroom has a level of 1.74 parts per million of asbestos. However, the class sides with Bart, as he demands more asbestos. At home, Homer reads Bart's class newspaper and is impressed with Bart's popularity. He encourages Bart to continue taking the election seriously and to go after Martin and win. A montage ensues, showing Bart leading rallies and posting pro-Bart signs and anti-Martin signs; all while a nervous Martin looks on in despair.
As Bart leads a demonstration outside, Lisa and Mr. Bergstrom observe through the classroom window. Lisa makes a comment about Bart's campaign antics, and Mr. Bergstrom tells Lisa that she will miss him, when she's older and off doing important things with her life. Lisa takes in every word he says with reverence. Later as class ends for the day, Mr. Bergstrom announces that the Springfield Museum of Natural History will be closing in two weeks, and he urges the students to visit it before it closes. Later at home, Marge suggests to Homer that she take Lisa to the Natural History Museum the next day. Homer tries to get out of doing it, but Marge cites that it will help his relationship with Lisa and he reluctantly agrees to take her.
The next day at the entrance to the museum, Homer discovers that patrons do not have to pay the suggested donation to enter, and he laughs at the receptionist, telling her that no one will pay the donation if they don't have to. Just then, Mr. Bergstrom enters the museum and places $5 in the donation box. Much to Lisa's embarrassment, Homer rushes over to tell Mr. Bergstrom that he doesn't have to pay if he doesn't want to. All three of them tour the museum together; Mr. Bergstrom shares his knowledge to an awed Lisa, while Homer keeps embarrassing her with stupid comments. Later as Lisa explores the museum alone, Mr. Bergstrom sits down with Homer to discuss Homer's relationship with Lisa. Mr. Bergstrom tries telling Homer that Lisa is a wonderful child and that he has to be a better male role model for her. But Homer misses the entire point of the conversation, he thinks the conversation is about Lisa's grades and he asks Mr. Bergstrom that, if Lisa is so wonderful, why not just give her an "A." Later at home, Lisa complains to Marge that Homer had ruined her best chance of getting to know Mr. Bergstrom outside of school. Marge comforts Lisa by telling her that she can invite him over for dinner. Lisa instantly falls in love with the idea and begins planning the dinner in her head. The next day at school, a nervous Lisa stands in the hallway before class and practices what she will say when she invites Mr. Bergstrom to dinner. But as she enters the classroom, she is horrified to see that Mr. Bergstrom is gone and that Miss Hoover is back.
Act Three: Miss Hoover explains to the class that she didn't really have Lyme disease, but that all the recent media hype about the disease made her think that she had it. She also comments to the class that she is upset with Mr. Bergstrom for not following any of her lesson plans. Upon hearing this, Lisa gets up and storms out of the classroom sobbing. Meanwhile in Bart's class, Mrs. Krabappel asks Martin and Bart for their final statements before the election. A worried and disheveled Martin says he has nothing more to say, and a confident Bart announces a victory party under the slide later.
By now, Lisa has made it across town and to the apartment complex where Mr. Bergstrom lives. Lisa buzzes his apartment and when she receives no reply, she begins calling out his name. Another woman living in the complex sticks her head out the window and tells Lisa that Mr. Bergstrom must have got another teaching job somewhere else and is probably headed out of town by train. Back at the school during recess, Bart goes around the schoolyard thanking everyone for their vote. But as he makes his way around, talking to people, he discovers that no one voted and that they assumed Bart was a shoe-in for president. Bart quickly panics and realizes he must get just a few people to vote, but before he can, the end bell for recess rings, and Bart screams in horror as he realizes the time to vote is over. Back in the classroom, Martin and Wendell cheer, and Mrs. Krabappel gloats to Bart by recounting the only two votes cast, both for Martin. Parodying the infamous "Dewey Defeats Truman" headline, the class newspaper photographer takes a picture of Martin holding up a headline that reads, "Simpson Defeats Prince."
At the train station Lisa tracks down and confronts Mr. Bergstrom, just as he boards his train. He apologizes for having to leave, but tells Lisa that he is needed in the projects of Capital City. Lisa fights back tears as she tells Mr. Bergstrom that he is the best teacher she will ever have and that she will miss him. Mr. Bergstrom writes Lisa a note, folds it and hands it to her, saying that whenever she feels alone or when she feels she has no one else to rely on, that she should just read the note. Mr. Bergstrom boards the train and as it pulls away he waves goodbye to a crying Lisa and tells her to read the note. As the train disappears, Lisa unfolds the note, it reads: "You are Lisa Simpson."
That night at dinner, Homer is upset and can't believe that Bart didn't win the election. He notices Lisa moping and gruffly asks her what her problem is. She tells Homer that Mr. Bergstrom is gone forever and when Homer doesn't seem to care, she erupts at him. She angrily calls him a baboon, and rushes upstairs to her room sobbing. Everyone is shocked, including Homer; Marge tells him that he is not allowed to have hurt feelings and orders him to go upstairs and make things right with Lisa. Up in Lisa's room an honest and sincere Homer apologizes to Lisa and explains that he doesn't know how she feels, because he has never lost anyone important to him and that everyone important to him lives under his roof. Lisa apologizes for calling him a baboon, and Homer tells her to think nothing of it. Homer walks out of Lisa's room and he stops in Bart's room as he notices Bart moping about the election. Homer tells Bart that the class president doesn't get paid or get to do anything cool and this cheers Bart up, as he realizes that he wouldn't have had any fun being class president anyway. On Homer's way out of Bart's room he walks past Maggie's room and notices Maggie whimpering in her sleep. He walks up to her crib and soothes Maggie by placing her pacifier in her mouth. Homer is impressed with his own parenting skill, after going 3 for 3 with his kids. Down in the kitchen, Homer approaches Marge and before she can say anything, he suggests that they just go to bed, because he is on the biggest roll of his life.
End Credits: The normal Simpsons theme plays as the credits roll over a black background.
Run Time: 22:56