"Dial 'N' for Nerder", also known as "N is for Nerder", is the fourteenth episode of the nineteenth season of the American animated television series The Simpsons. It originally aired on the Fox network in the United States on March 9, 2008. After a prank gone wrong, Bart and Lisa believe they have accidentally killed Martin Prince. Meanwhile, Marge hires a TV show called Sneakers to spy on Homer and see if he is cheating on his diet. The episode was written by Carolyn Omine and William Wright and directed by Bob Anderson. During its first broadcast, the episode had an estimated 7.3 million viewers and received a 10 percent audience share.
Plot
Homer and Marge are in bed about to have sexual intercourse, but Homer is too overweight to do so. When he arrives home for dinner the next evening, Homer is surprised to see that Marge has hired a formerly obese nutritionist named Betsy Bidwell. She puts Homer on a strict diet consisting solely of bell peppers. Although Homer appears to stick to the diet, he gains seven pounds, and Marge suspects that he has been cheating. Later, while the kids watch TV, Marge sees an advertisement for a television show named Sneakers, a parody of Cheaters designed for couples who are cheating on each other. Someone on the advertisement says to call the Sneakers hotline if they suspect cheating, which Marge realizes she can use to find out about Homer.
Bart and Lisa, sent out of the house by Marge so she can make an "adult phone call" to Sneakers, tour Springfield National Park. At the top of a mountain, the two discover Martin excavating for arrowheads. While Lisa joins him in excavating, a frustrated Bart plays a prank on Martin. Stealing Sideshow Mel's bone (revealing that he actually has long flowing hair), Bart buries it. Martin arrives thinking it is a real artifact. Bart tugs on a string connected to the bone, which flies up to knock Martin in the head. He stumbles over the edge of the cliff, and falls onto a smaller ledge. Lisa takes a long stick and tells him to grab onto it, but inadvertently knocks him off the ledge, and he falls into the trees at the bottom of the cliff. The two return home believing that they have killed Martin, and feel guilty and unsure what to do. On the news, Kent Brockman reports Martin has disappeared and is presumed dead. Chief Wiggum says when Martin landed he was eaten by a cougar. Bart, feeling guilty, wants to admit his crime to pay the price, but Lisa, frightened of going to jail for being an accomplice, convinces him to keep quiet. Homer is about to leave the house, claiming he is going to work on a Saturday. Marge calls Sneakers, which prompts a nearby van full of Sneakers agents to stalk Homer.
A memorial is held as a tribute to Martin in the school gym. Nelson realizes that Martin had a fear of heights so it would be unusual for him to be at the top of a cliff. Nelson travels to Springfield National Park and discovers Sideshow Mel's bone on a string. Meanwhile, the Sneakers agents catch a video of Homer going to a restaurant. Marge confirms her suspicions of Homer but realizes that the reality show people do not care about their marriage, and if anything, are trying to destroy it. She quits the show and embraces Homer, while the host goes off and edits the episode to make Marge look crazy.