Butters must fake his death, dress up as a girl and infiltrate Heidi Turner's slumber party, in order to retrieve a "future telling device" that Cartman and the other boys are convinced is real.
Cartman gathers the boys in his basement and shows them a videotape in which he caught footage of the girls using a cootie catcher (also called popper or a fortune teller) to predict the future. Not knowing it's only a game, he believes that the girls possess a secretive, high-tech future-telling device. Cartman tells the other boys that they must try to steal it from them.
They construct a containment center, complete with bio suits, a quarantine shower and a housing unit to store the "device" in order to study it. They then come up with a plan on how they're going to steal it.
They deduce that the girls will be using the device at Heidi Turner's sleepover party, and they arrange for one of the boys to go to the party disguised as a girl. Unsurprisingly, this unpleasant duty falls to Butters. They then have Butters stand at the top of a skyscraper, declaring that he is going to end his life by jumping off. In reality, the boys drop a pig carcass dressed like Butters over the edge. Cartman says that this way, no one will be concerned with Butters' whereabouts while he's pretending to be a girl. At Butters' funeral (with the pig in the coffin) Linda Stotch becomes entirely hysterical with grief at her son's apparent death, throwing herself on his coffin and screaming as Stephen Stotch holds her back from the grave.
The next morning, Butters arrives at school dressed as a new girl named Marjorine. Heidi's mother later tells her that she received a phone call from Marjorine's mother (who was really Cartman) asking if Marjorine could go to the party. "She" apparently said that she works as a governor's assistant, and that Mrs. Turner should respect her authoritah (authority). Butters, having little idea of what to do at girls' parties, is very awkward. After Marjorine screams in fear as the girls play "Light as a feather, stiff as a board", they insult her about her clothing and body. This causes Butters to get upset, and he runs into Heidi's bathroom crying; he locks himself in. Wendy and Bebe, who were gentler than the other girls, say that they were probably too hard on Marjorine, saying that "it must be tough being the new kid", causing the girls immediately realize that they were wrong to tease her like they did. They persuade Marjorine to come out of the bathroom, then they give her a makeover, and invite her to dance.
In the meantime, Linda is still in deep mourning over losing Butters, much to her husband's distress. A farmer who resembles the Jud Crandall character from Pet Semetary, and who appeared in "Butters' Very Own Episode" and "Asspen", tells Stephen not to dig Butters' corpse up and re-bury it in the old Indian burial ground, thereby informing Butter's father about the cemetery which Stephen didn't know about in the first place. In a nod towards the movie, he says, "Don't do it Stotch! Sometimes, what you take out of the ground ain't the same thing you put in!" However, Stephen performs this deed anyway, in hopes that it will bring Butters back to life.
After failing to hear from Butters, the boys check on him by looking in the window only to find that he (as Marjorine) is having fun and (having clearly forgotten why he's there) dancing to "Rock Your Body" by Justin Timberlake. Heidi's father spots Craig, who is using binoculars to look in on Butters. Butters, thinking that he's been found out, quickly snatches the device, and leaves. Unable to understand what happened, Heidi simply asks for some paper to make another one.
Butters quickly gives the device to the other boys, before going home to tell his parents that he's not really dead. The boys decide the power of possessing the device is too great and dangerous for them to withhold. They decide to have Kenny blow up the device rather than defend it from the girls, the CIA, terrorists and Russians. The resulting explosion is visible from space.
Butters' parents are convinced that he will now return as a demon, and when he comes home, they lock him in the basement. When he tells them he's hungry, they kill a woman named Rachel, who worked for a curtain company, and drop her at his feet, then leave so he can feed on her. He then asks, "Can I just have some Spaghetti-O's?".