"Treehouse of Horror VIII" is a Halloween-themed episode from the ninth season of the animated comedy series The Simpsons. It was first broadcast in the United States on the Fox Network on October 26, 1997.
In common with all the previous Simpsons Halloween episodes, the program is made up of three self-contained stories; "The Homega Man", "Fly vs. Fly" and "Easy-Bake Coven". In "The Homega Man", Homer Simpson appears at first to be the only person left alive on Earth. He then discovers that other people have survived but have been mutated. The segment is based on the 1971 movie The Omega Man. The aliens Kang and Kodos make a brief appearance in the story. In "Fly vs. Fly", Bart Simpson's head gets transferred to the body of a fly and the fly's head is placed on Bart's body. The segment parodies the 1958 movie The Fly. In "Easy-Bake Coven", a 17th-century version of Marge Simpson is accused of witchcraft. The segment spoofs the 1996 movie version of Arthur Miller's The Crucible.
A censor tells the audience that he has edited the episode to make it safe for family viewing. An icon in the top left-hand corner of the screen shows that the episode is rated "TV-G". An arm with a sword emerges from behind the icon and begins stabbing the censor in the back. With each stab, the rating changes to an increasingly less family friendly one. When the arm has finished stabbing the censor, the rating has become the satanic "TV-666".
The "couch gag" sees the Simpsons get shackled to their couch and electrocuted.
"The Homega Man"
The mayor of Springfield makes some offensive remarks about France and refuses to apologise for them. In retaliation, the French launch a neutron bomb which makes a direct hit on Springfield. At the time that the bomb drops, Homer Simpson is inspecting a bomb shelter which he is considering buying. He consequently becomes the last human left alive. Homer is sad at first that he has lost his wife and children but soon becomes ecstatic when he realises that he can do whatever he likes without anybody stopping him.
Homer later discovers that everybody did not die in the bomb blast. Many of the people of Springfield have become mutants. They approach Homer and tell him that they plan to create a perfect society in which the mistakes of the past have been eliminated. Unfortunately for Homer, the mutants consider him to be one of the mistakes of the past and intend to kill him.
The mutants chase Homer to his former family home. His wife Marge and children Bart, Lisa and Maggie emerge from the house alive, unmutated and unharmed. Marge says that they were protected by the house's several layers of lead paint. The mutants are touched by the emotional reunion of Homer with his family. They see the error of their ways and suggest that humans and mutants can live together in harmony in their new society. Marge and the children show their contempt for that idea by producing shotguns from behind their backs and firing at the mutants.
"Fly vs. Fly"
Scientist Professor Frink holds a yard sale at which Homer Simpson buys a teleportation device. He uses it primarily to get beer from the kitchen refrigerator while still sitting on the living room couch and refuses to let his son Bart play with it. At night, Bart secretly tries to test the machine on the family cat. The family dog enters at the same time. Two creatures emerge from the machine. The first has a dog's head at one end of its body and a cat's head at the other. The second has a tail at each end.
When a fly lands on Bart's arm, he gets the idea to use the machine to merge himself with it, thinking that he will become a flying superhero with enhanced vision. When he comes out of the machine, Bart's head has become tiny and attached to the body of the fly. The fly's gigantic head is on Bart's body. The family wake up and see the fly-headed creature. They assume it is Bart and vow to continue treating him as normally as possible. Bart tries to coax the fly into getting back into the machine with him but the fly tries to eat him.
Bart manages to tell his sister Lisa the truth of the situation, using Lisa's saxophone to amplify his voice. Having overheard their conversation, the fly chases Lisa into the kitchen and starts to attack her. Bart tries to stop the fight but is eaten by the fly. Lisa sees that she has the opportunity to put things right and pushes the fly into the transporter. Bart and the fly, restored to normal, emerge from the machine.
The segment ends with Homer Simpson getting an ax. Instead of using it to destroy the dangerous machine, he uses it to chase Bart, still being angry at him for playing with the teleporter.
The final story in "Treehouse of Horror VIII" takes place in the town of Sprynge-Fielde in the year 1649. Many people in the town have been accused of being witches and have been executed by burning. The town's people gather in the church to decide who to accuse next. They all begin to accuse each other and the meeting quickly descends into chaos. Marge Simpson tries to calm the situation down and reason with the people but gets accused of being a witch herself.
The mayor explains to Marge that she will be given the opportunity to prove that she is not a witch. She is given a broomstick and told that she will be pushed off a cliff. If she is innocent, she will die a good Christian death. If she is guilty, she will be able to fly to safety, and will be obliged to report back for punishment later. To the surprise of her children, a green-skinned Marge flies the broomstick back to the top of the cliff, announces that she is indeed a witch and flies away.
Marge returns to the home of her sisters, who are happy that she has finally left her human husband Homer, in a cave at the top of a mountain overlooking Sprynge-Fielde. The witches use a magic cauldron to spy on the people of the town. They overhear Maude and Ned Flanders saying that the witches may plan to eat their children. The three witches decide that is a good idea and fly down to the town to do just that. When the witches arrive at the Flanders' house, Maude offers them gingerbread children instead of her sons. The witches prefer the cookies to the children and gladly accept them. At the other houses in the town, the witches are given candy in exchange for not eating the occupants' children.
It is explained that the witches bribing people into giving them candy was the origin of trick-or-treating and Halloween. One year later, all of the people of Sprynge-Fielde are out trick-or-treating in their costumes on Halloween night. Homer Simpson is seen throwing eggs at a house, claiming that the people who live their did not give him any candy. When his daughter Lisa points out that it is their house, he acccuses of her of being a witch and she is chased by an angry mob.