In common with all the previous "Treehouse of Horror" episodes, the program is made up of three self-contained stories; "Hex and the City", "House of Whacks" and "Wiz Kids". In the first story, Homer Simpson is cursed by a Gypsy. The second story spoofs both the 1968 science-fiction movie 2001: A Space Odyssey and the similar 1977 horror movie Demon Seed. The story involves an intelligent, sentient computer falling in love with Marge Simpson and seeking to replace her husband Homer. The final story is a parody of the Harry Potter series of books and movies, in which the Simpsons regular characters Mr. Burns and his assistant Smithers become the evil Lord Montymort and his snake-like sidekick Slithers.