Marge warns that the episode is frightening and children should not watch it. During the warning, she is told that it is so scary that Congress will not let them show it. Bart interrupts it with a radio transmission and shows the episode.
In a parody of The Shining, The Simpsons go to Mr. Burns' mansion to become its caretakers. Burns cuts the cable television wire and removes the beer, believing that this will ensure hard work from the family. While there, Groundskeeper Willie discovers that Bart has the power to read his thoughts and that if Homer goes insane, he should use this to call him. The absence of his two favorite things sends Homer insane and a ghostly Moe tells Homer he must kill his family in order to get a beer. Marge finds that Homer has covered the walls with the repeating phrase "No TV and no beer make Homer go crazy", and confronts Homer with a baseball bat, but Homer, seeing his reflection in a mirror, trips and knocks himself unconscious. Marge locks him in the pantry until he has calmed down and makes some chili for dinner. Later on, Homer has calmed down and happily eats, but Moe reminds him of their deal through the pantry door. When he refuses to cooperate, Moe shows up with his gang of ghouls and carries Homer out much to his dismay. As Marge and the children are enjoying dinner, Homer begins chasing the family with an axe and Bart uses his powers to call Willie, who runs to the family's rescue, dropping his portable television in the snow. Homer kills him by stabbing him in the back with the axe. Homer chases his family outside but just as he is about to kill them, Lisa shows him Willie's discarded television. Homer's insanity gradually fades and the family freezes in the snow while watching with him. With the family unable to change the channel when the Tony Awards begin, Homer's insanity rises again.
In a parody of A Sound of Thunder, while trying to fix a broken toaster, Homer accidentally turns it into a time machine. It transports him to prehistoric times where he realizes he must be careful because if he affects anything in the past, it could change the future. After swatting a mosquito, he returns to the present to find a dystopia where Ned Flanders is now the dictator of the world. Homer travels back in time again to try to set things right; however, he accidentally kills a walking fish, and after returning to the present he finds Bart and Lisa are giants, narrowly avoiding being crushed by them. He then sneezes and infects the dinosaurs with a cold virus while defending himself from a Tyrannosaurus Rex, which proceeds to cause their extinction. He is initially pleased with the results in the present; amongst other perks, the family is now extremely wealthy and Patty and Selma are dead, but is terrified to find that donuts do not exist in this timeline and flees, seconds before donuts begin raining from the sky. In another world, Willie tries to help Homer, but is again hit in the back with an axe, this time by a James Earl Jones-voiced Maggie. When Homer returns to the prehistoric times again, he furiously smashes everything in sight with a baseball bat. After several more trips back and forth in time, Homer eventually arrives in a reality that appears normal; he finds that humans eat with lizard-like tongues, but decides it is "close enough".
In a parody of Soylent Green, Principal Skinner is concerned that the detention hall is becoming overcrowded and as a result of the latest budget cut, Lunchlady Doris is being forced to serve "Grade F" meat in the cafeteria. Skinner discovers a common solution: eating misbehaving children. The first student to be eaten is Jimbo Jones, who is served as "Sloppy Jimbo", followed by Üter, who is then transformed into a German meal called "Üterbraten". Bart and Lisa figure out what the teachers are doing, but one by one, the kids are "sent to detention" where they are caged and butchered. The kids turn to Marge, who tells them that they must stand up for themselves. Eventually Bart, Lisa and Milhouse are among the only students remaining and attempt to escape. Skinner and the other teachers corner them on a ledge above a giant blender. Willie attempts to help the students escape, but is once again killed with an axe in the back, this time by Skinner. Milhouse, Bart, and Lisa fall to their demise.
Bart wakes up from the nightmare to find his family beside his bed. Marge assures him he has nothing to be afraid of, but a green fog seeps through the window and the Simpsons are turned inside out. They, along with Willie, perform a musical number over the end credits, but Bart is dragged away by Santa's Little Helper.