Bart, Milhouse, and Nelson spray-paint a street number onto a curb in front of a house. Bart figures that the owners of the house will want to pay them for their work. Suddenly Moe runs out of the house, shotgun in hand. He fires several blasts, demanding to know what the boys are up to. When he finds out they spray-painted his house number on the curb, he softens and hands the boys a $10 bill. Ned Flanders is equally impressed. He offers the boys $50 to spray-paint his garage. Horrified by the idea of making an honest wage, Bart and his friends run off. The boys spray-paint a number in front of the Simpson house, but Homer refuses to pay up. The boys leave the number one digit short (only the “74” has been painted; the “2” is missing). Homer makes the best of it by adding, “74 Oakland A’s—The Best Team Ever.” This attracts the attention of some retired Oakland A’s players. Lisa points out that no one is going to be able to find their house. Before long the mail lady begins delivering the family mail from another address. Among the envelopes is an invitation to a wedding, which Homer and Marge end up attending. Later Marge opens some mail, and discovers that she’s won Homemaker Magazine’s “Clean For a Day” contest; the prize: a maid will come to the house and clean. Marge is puzzled, as she doesn’t subscribe to the periodical. Nonetheless, she scrubs the house clean before the maid arrives, as she doesn’t want a stranger to think she lives in a dirty house. Marge accidentally mixes together different cleaning solutions, and the fumes cause her to faint and hit her head on the floor. Marge is taken to a hospital, where it soon becomes apparent that she suffers from amnesia.

Dr. Hibbert tells Homer he has to jog Marge’s memory until she returns to normal. Homer takes Marge on a tour of Springfield, hoping it will help her remember who she is. They pass Sideshow Mel, Bumblebee Man, the Sea Captain, and Duffman as they engage in a “chicken fight,” but Marge doesn’t remember them. She also doesn’t remember Otto, the school bus driver, who drives his bus off a cliff and into a lake. Homer takes Marge home. Marge instantly remembers baby Maggie when she hears the sound of her pacifier suck. Moments later she remembers Lisa, Bart, and Milhouse… and just about everything else about her old life. The one person she doesn’t remember is Homer. Marge turns to her sisters, Patty and Selma, who tell her it’s a sign she should leave Homer forever. Homer decides that if he can’t make Marge remember him, he’ll start from the beginning and make her fall in love with him all over again. Try as he might, Homer’s attempts at wooing Marge lead nowhere.

Since Marge can’t remember anything about Homer, she asks him to leave the house. Homer is forced to share a room with his father at the retirement castle. Patty and Selma arrange for Marge to attend a singles mixer at a local hotel. Marge hits it off with a good-looking bachelor, who invites her out for some coffee. Lenny and Carl spot Marge at a café with the good-looking bachelor. They phone Homer, and warn him about what’s going on. Homer races to the café, where he resigns himself to the fact that Marge has found someone who can finally make her happy. When Marge admits she has three kids, the good-looking bachelor quickly says goodbye. Homer confronts the good-looking bachelor, and tells him he’s making a big mistake by walking away from someone as wonderful as Marge. Marge is impressed with Homer. She gives him a kiss, and they drive off together.