In "Treehouse of Horror XXIII," Marge and Homer go back to ancient Mayan times and learn that the world will come to an end in 2012; and a glitch in the Springfield Subatomic Supercollider wreaks havoc on the city; Marge as a youngster has a devil of a time after entering into a satanic pact; and Bart travels back to 1974 for a chance to buy a comic book at its cover price, and inadvertently puts a hitch in Homer's courtship of Marge.