Opening Credits: Blackboard joke: I am not a dentist. Couch gag: The family runs in and sits down, their weight tips the couch backward and the family tumbles through the wall behind the couch.
Act One: Very early on a school morning, Lisa wakes Bart up in his room and reminds him that in two days she will turn 8 years old. She hints around at the importance of receiving a birthday present from him and he hastily tells her not to worry. Downstairs in the kitchen, Bart eats his breakfast, while Marge folds some laundry. A shirtless Homer rushes into the kitchen, searching for his white shirt. Marge tells him to calm down, as she reaches into the laundry basket and pulls out a shirt for him. However, the shirt is pink, and Homer begins to panic. As he sorts through the rest of the laundry, he is shocked to discover that all of his white shirts have turned pink. He explains to Marge that he isn't popular enough to stand out in the crowd and wear a pink shirt to work. Bart happens by the laundry basket and pulls out his lucky red cap. As soon as Homer realizes that is was Bart's hat that turned his shirts white, he immediately begins strangling Bart. Marge calms Homer down and convinces him that no one at the power plant will even notice the pink shirt.
At the power plant, Mr. Burns and Smithers scour the security camera footage with their new color monitors, and Mr. Burns spots Homer like a sore thumb, with his pink shirt. He demands to know who the man is and why he is wearing pink. Smithers informs Mr. Burns that the man is Homer Simpson and Mr. Burns feels that Homer's seemingly free spirited and expressive style is unwelcome at the plant. Smithers orders security to grab Homer. Meanwhile, Homer nervously walks through the halls of the plant, as everyone points and whispers about his pink shirt. Homer makes his way to a break area, where Carl and Lenny tease him, by saving Homer a single pink frosted doughnut. Just as Homer is about to take a bite, security grabs Homer and escorts to him a secluded room in the plant.
Homer sits in a dimly lit room surrounded by two guards, Mr. Burns, Smithers and Dr. Marvin Monroe. They all seem to think that Homer's sanity is in question, for wearing a pink shirt to work. Homer tries to explain about Bart's red hat mixing with the laundry, but Mr. Burns won't hear any of it. Dr. Monroe hands Homer a copy of his patented take-home personality test that will determine the level of Homer's saneness. Homer looks at the test and seems overwhelmed about successfully passing.
At home, Homer brings his test to Marge and tries to get her to fill it out for him. She looks at the test and tells Homer that he has to do it, because it is a test to determine his personality profile, not hers. Homer instead tries to get Lisa to fill out the form; she agrees, but in exchange, Homer must listen to her recite a poem she has written. After a few boring verses, Homer calls off the deal and heads downstairs, to see if Bart will fill out the test for him. Bart takes a look at the form and tells Homer that he should probably fill out the form himself, but Homer convinces him to go ahead anyway. Bart has fun with the test and quickly answers "yes" to all the "yes" or "no" questions on the test. The next day at the power plant, Dr. Monroe, Mr. Burns and Smithers review Homer's test results. A nervous Homer asks if he passed, Mr. Burns answers, "No," and the security guards quickly grab a hold of Homer, throw him in an ambulance and rush him to the New Bedlam Rest Home for the Emotionally Interesting.
Homer is examined by the head doctor at the asylum, who administers an ink blot test. Homer correctly identifies the first couple of ink blots, but when he sees an ink blot that looks a lot like Bart's face, Homer becomes furious. Two guards quickly grab Homer by the arms and the head doctor stamps "Insane" in red ink on the back of Homer's hand. The two guards take Homer to his cell that is already occupied by a tall, large, white man. The guards slam the door shut behind Homer, and Homer's roommate, a giant of a man, approaches and introduces himself as Michael Jackson. The giant man eerily sounds just like the real Michael Jackson.
Act Two: Homer and Michael converse in their cell and Michael cannot believe that Homer has never heard of him. Michael performs a few lyrics from Billie Jean, complete with a Moonwalk and a crotch grab. However, none of this rings a bell to Homer, who is oblivious to the fact that this giant white man thinks he is the real Michael Jackson. Meanwhile, at home, Bart and Lisa watch an Itchy & Scratchy cartoon (Titled: Bang the Cat Slowly). The cartoon features Itchy the Mouse giving Scratchy the Cat a lit bomb for a birthday present. Lisa uses this opportunity to remind Bart about the birthday present that he promised to get her. Bart once again reassures her that he will get her a present.
Back at the asylum, Michael gives Homer a tour around the common area and introduces him to some of the inmates. Homer spots a phone and decides to call home; however, he feels embarrassed about calling from an asylum, so Michael offers to call home for him. At the Simpson home, Bart answers the phone, and he is surprised to hear someone that sounds just like Michael Jackson on the other end of the line. After Michael convinces Bart that he is the real Michael Jackson, by naming his last four dates for the Grammys, he explains Homer's predicament. Bart, who is more interested in having spoken to Michael Jackson, takes down the message and delivers it to a shocked Marge. Marge promptly calls the asylum, but she can't get through to an operator, as all the lines are busy. That night in his cell, Homer confesses to Michael that he is scared about being locked up in the asylum and Michael puts Homer at ease, by singing him a lullaby.
Act Three: The next day at the asylum, Homer is forced to attend a group therapy session, while Marge pays a visit to the head doctor at the asylum. Marge pleads with the doctor, who is insistent that Homer is insane. Marge explains to the doctor that as long as you don't mention Bart's name, Homer is fine. The doctor realizes that she is right, after learning that Bart really does exist. In the common area, Homer sits down to a big plate of pancakes, when Marge walks in. The two embrace and the head doctor hands Homer a certificate of sanity and tells him that he is free to go. Homer tells Michael that if he ever gets out of the asylum, he should pay the Simpson family a visit. Michael tells Homer that he will visit him today and explains that he checked in to the asylum voluntarily, and therefore, is free to go whenever he wants to. Meanwhile, at home Lisa sits with Maggie at the kitchen table and sadly sings "Happy Birthday" to herself.
Homer calls home and Bart answers, Homer tells Bart to break out some cold cuts and put the beer on ice, because Michael Jackson is coming home with him. Michael tells Homer to make sure that Bart understands not to tell anyone that he is coming, and Bart promises to keep Michael's visit a secret. However, as soon as Bart hangs up the phone, he calls Milhouse to tell him the good news. Milhouse in turn calls some more people, and soon the news is all over Springfield that Michael Jackson is coming to the Simpson home. Nearly the entire town of Springfield, the Mayor and the press quickly descend upon the Simpson home, and await Michael Jackson's arrival. The crowd whips into a frenzy, as Marge arrives back at home, with Homer and Michael in tow. However, when Homer introduces Michael to the crowd, the cheers quickly become boos, as they see the large, tall, white man, who is not Michael Jackson. The crowd clears out as quickly as they came and Bart and Lisa are left standing in their littered front lawn. Lisa approaches Bart and informs him that today is her birthday; Bart casually tells her that he didn't get her a birthday present and a crushed Lisa runs away crying.
Upstairs in the bathroom, Homer unsuccessfully tries to scrub his "Insane" stamp off of his hand, as Michael watches from the doorway. Michael heads down the hallway and notices Lisa in her room writing an angry letter to Bart, informing him that she plans on cutting off all contact from him in the future. Michael heads down the hallway a little further and enters Bart's room. Michael explains to Bart, that when he was a kid growing up, he didn't have much money, so he always wrote a song as a birthday present for his sisters. A reluctant Bart points out to Michael that he isn't the real Michael Jackson. But, Michael persists and Bart agrees to write a song for Lisa with Michael's help.
Downstairs, Michael sits at the piano while Bart struggles to write some lyrics. The two stay up most of the night working on the song and after a few failed attempts, they are finally successful. Bright and early the next morning, Michael and Bart wheel the piano into Lisa's room and wake Lisa up, to present her with the song. Bart uses an upside down wastepaper basket as a makeshift drum, as Michael accompanies him on the piano. The two sing a "soft pop" sounding song for Lisa; the sound reverberates throughout the house, waking up Homer, Marge and Maggie. They all stand in the doorway, as Michael and Bart finish Lisa's song; Lisa, who loves the song, thanks Bart with a giant hug. She thanks Michael as well and Michael replies in a rough east coast accent, saying, "Well, my work is done here." Everyone is shocked at Michael's voice, and Michael explains that his real name is Leon Compowski, and that he is a bricklayer from New Jersey. He goes on to explain that all his life he was an angry person, until one day he decided to talk like Michael Jackson. From that point forward everyone always seemed to smile at him and he felt good about himself, so he kept on using the voice and took up Michael's persona. Outside on the front lawn the Simpson family waves goodbye to Leon, who strolls away down the sidewalk humming Lisa's birthday song.
End Credits: Michael and Bart sing Lisa's birthday song and Lisa plays a saxophone instrumental, as the credits roll over a black background.
Run Time: 23:00