 “ Treehouse of Horror XII ” is the first episode of The Simpsons ' thirteenth season . Because of Fox ’ s contract with Major League Baseball ’ s World Series , the episode first aired on the Fox Network in the United States on November 6 , 2001 , nearly one week after Halloween . It is the twelfth annual Treehouse of Horror episode , consisting of three self @-@ contained segments . In the first segment , a gypsy puts a curse on Homer , which puts everybody he cares about in danger . In the second segment , which is a parody on both 2001 : A Space Odyssey and Demon Seed , the Simpson family buys a new house , who falls in love with Marge and attempts to kill Homer . In the third and final segment , which lampoons the Harry Potter franchise , Lord Montymort attempts to capture Lisa , a skilled magician , in order to drain her magic powers . 
