Homer grows despondent when the Denver Broncos win the football game he’s watching on television. He tells Lisa he bet money on their opponents because of what he read in “Professor Pigskin’s Pick of the Week.” Homer strongly believes in the prescient pig’s predictions. Lisa warns her father that the whole thing is a scam. Despite Lisa’s concerns Homer bets heavily on an upcoming game, and pays for the bet using money he borrowed from Fat Tony and his gangster cohorts. When Homer’s team, the Oakland Raiders, ends up losing, Fat Tony assures him they can work something out. As Fat Tony’s goons smash Homer’s knuckles with a hammer, Fat Tony suggests that Homer settle his debt by allowing the mob to shoot a pornographic movie inside his house. Homer tells the gangster that Marge would kill him if she found out. Afterward Homer makes his way to Moe’s bar, where he tells the barflies about his dilemma. Moe hands him some free tickets to Santa’s Village, and suggests that Marge take the kids there while the movie is being made. Despite the fact that it’s August, Marge and the kids go to the village, where Santa lies in a lounge chair with his shirt off. Marge is so disappointed she decides to spare the kids further torment by leaving early. The shooting of the pornographic movie gets underway at the Simpson house. Carl and Lenny drop by to borrow a board game, only to land roles in the film. A short time later Marge enters the house and realizes what’s going on. Furious, she storms out. She drives off in the car, telling Homer it’s up to him to watch the kids. Bart tells Homer he’s never seen Marge so mad.

Homer sits around the house, unsure if Marge will ever return. Marge pulls into a rest stop, where she decides it’s time to call home. As she speaks with Homer an unseen stranger bangs on the door of the phone booth. Marge turns around and sees an enormous, walrus-like sea creature looming over her. A man we’ll come to know as Doctor Caleb Thorn quiets the animal by feeding it some kelp. Thorn tells Marge he’d do just about anything to aid a manatee. Caleb tells Marge that she has two major obstacles in her marriage. One is that that Homer knows she’ll always take him back. The other is that Marge thinks she can change Homer. After giving it some thought, Marge declares that she’ll no longer accept second best. She and Caleb make their way to the coast, where they don wet suits and swim with manatees. Marge bonds with one of the creatures even though it spews up a large stream of dirty green water and has gunk in its ears. As Marge hugs the manatee, it suddenly makes its way out to sea, taking her along with it.

Homer and the kids embark on a journey to find the missing Marge. Homer decides to stay with his cousins, whom he describes as “rubes.” When Homer, Bart, and Lisa arrive at the farm, their relatives — Uncle John, Aunt Kathy, and their son Randy — turn out to be anything but hillbillies. As Lisa gazes through a telescope, she spots Marge floating out to sea. Homer makes his way to the beach, where Marge sits with Caleb. He hands her a beautiful bouquet of flowers and a box of candy. Marge accepts his apology and kisses him on the cheek. The show’s closing theme begins to play, but suddenly Marge announces that she’s not ready to return home quite yet. She tells Homer she’s finally found a place where she’s needed, and can’t find it in her heart to go home. Homer angrily accuses Caleb of stealing away his wife. Caleb assures Homer he has no designs on Marge. Then he warns that Marge has found something she’s always needed: a purpose. Homer regroups with the kids. He tells them that the solution to the problem involves the manatees. Bart alerts Homer to some nearby jet skiers, who are headed for a herd of manatees. Using a paddleboat Homer makes his way to the herd, where he tells the jet skiers to pick on someone their own size. He wins their respect when he declares that he’s trying to win back his wife. When he refers to the jet skiers as “rubes,” they pull out switchblades and tire chains and descend on Homer. Luckily Uncle John arrives in a speedboat. He tells the jet skiers he has a court order requiring them to vacate the area. Uncle John and Randy use a stretcher to carry the beaten Homer to the boat dock. Marge runs up, proud that Homer sacrificed himself for the manatees. Realizing he’s won back Marge’s heart, Homer gets off the stretcher and walks away with her, arm-in-arm. Homer tells Marge they can go on vacation, assuring her that a friend can fill in for him at work. The scene shifts to the nuclear power plant, where a manatee sits at Homer’s workstation.