Handlung

When Maggie is revealed to have an IQ of 167, Lisa is no longer the genius of the family, causing a rivalry between the sisters.

After a quarrel with Dr. Hibbert, Homer decides to enlist Maggie for a pre-nursery school. Maggie doesn't get tested because she can't talk. Back home Lisa discovers Maggie can make words and the family goes back to the pre-nursery school. This time Maggie passes the test gloriously and turns out to have an IQ of 167. This is more than Lisa's IQ (159) which makes her unsure about her identity.—Marco van Hoof <k_luifje7@hotmail.com>

The episode begins with Bart going into the bathroom and Homer is excited about the prank he is going to play on him. Bart then walks out and says he didn't need to use the toilet seat as he is a "dude" and Homer tries forcing him on the toilet, only to fall victim to his own prank. Homer and Bart start fighting, until Marge asks what is going on and the two run into the hallway and Homer says he is taking the family out to get pancakes. When they arrive, they see Apu and Doctor Hibbert in a line for Mrs Wickerbottoms pre-nursery school and Marge walks in with Maggie. Unfortunately, as Maggie cannot speak she is rejected by Henry. Back at the simpson household, Maggie and Lisa play and Maggie answers Lisas questions, using her letter blocks. Lisa says she is brilliant and carries her out of the room. Back at Mrs Wickerbottoms, Henry gives Maggie an IQ test and calls in his co-worker Phillipa into the room and Henry says that she has an IQ of 167 and Lisa struggles to figure out how she is smarter than her. In the Simpsons living room, Marge goes through a box of stuff that the school sent over for Maggie, including a t-shirt for Lisa which read "I'm with genius" and one for Maggie which says "I'm with jealous". Up in her room, Lisa lays sad and tells Marge she doesn't know who she is if she's not the smart one and after Marge writes her a note, she says that Lisa can always go for a new identity. The following day, Lisa tries out a bunch of different identities, such as a comedian, a goth girl and a soccer player. Later on the bus ride home, Lisa says she is "a mess". Back at home, Homer plays with the phonic frog and goes to the phone to call in sick using the frog. Meanwhile, Lisa "helps" Maggie with her flash cards, but purposely teaches her the wrong word, before Marge catches her and tells her that she shouldn't teach her anymore and Lisa runs up to her room crying. That night, Lisa has a nightmare of her throwing grown up Maggie down the stairs, before running away. Outside the quick-e mart Principal Skinner says that no one has started a new life under $1.00, of which Lisa does not have. Meanwhile, Marge has called the police and Marge signs a survey and the cops go and get some smoothies, instead of searching for Lisa. Lisa decides to start her new life at a museum, before crying herself to sleep on a giant tongue saying she misses her family. The following day Homer, Marge and Bart put up flyers with Lisa's face on it, until the police say they have found Lisa's belongings at the museum. When they arrive at the museum, Homer, Marge and Bart search around the giant skeletons tongue, before Maggie presses a button making the giant skeleton swallow them. The trio try getting Maggie to push the red button, but all of their attempts fail. Marge, Homer and Bart start to drown in the stomach acid and Maggie starts to cry, until Lisa comes and apologies to Maggie for being so jealous of her and promises to nurture and cherish her, until Marge reminds her that they are drowning and Lisa pulls on her red dress and Maggie recovers the family from the giant. Back at the house, Lisa questions why Maggie didn't press the button until she told her to and Henry and Phillipa walk in and show them a video of Maggie looking over to Lisa for every answer and Lisa subconsciously giving her the answers. After Henry calls Maggie not a genius, Homer punches him in the chin, before knocking him out and Moe dressed as a butler and Barney as a maid drag him outside. The episode ends with Lisa saying that Maggie is still a genius to her, before Maggie starts playing Lisas saxophone and Lisa grabs it and says it is "not for babies". As the credits roll, Simon Cowell, who played Henry criticizes everyone who worked on the show and calls himself "a real celebrity".