time together around Springfield. Lisa realizes that the explosion opened a hole in the space-time continuum and tells Homer to recreate the explosion to fix it. They head to the Nuclear Power Plant to do so, but Mr. Burns stops them. Versions of Burns and Smithers from other dimensions fight the Homers and win. When Burns learns from a Noir version of Smithers that the Burns of his world is his assistant, he gives in and sends the alternate Homers, Burns and Smithers back to their own dimensions. As a side-effect, Homer begins shifting into the forms of his counterparts. Be Nine, Rewind In a parody of Russian Doll, at her ninth birthday party, Lisa keeps dying and restarting the day. She then learns that Nelson is experiencing the same thing, and that they both have to be alive at the same time in order to live. They try to end the loop by seeking help from Comic Book Guy, but none of his ideas work. So they realize the only way to end it is to kill Gil Gunderson, which they manage to do. Lisa returns home to properly celebrate her birthday. At home, everything is back to normal except that Ralph's head is backwards. Production Development A clip from the episode was shown during The Simpsons panel at Comic-con @ Home. An extended clip was released during an interview with showrunner Al Jean. The segment "Toy Gory", was animated entirely in CGI, which marks the first time the series has used that animation style since "Treehouse of Horror VI" in 1995. Initially, when first animated, the episode did not include the characters wearing masks, however, to reflect on the COVID-19 pandemic, showrunner Al Jean asked director Steven Dean Moore to have every character except Homer wear a mask. Ben Mankiewicz appears in the episode as himself. Release In 2020, Fox released 13 promotional pictures from the episode. The episode was originally scheduled to air on October 18, 2020, however, due to being preempted by game seven of the 2020 National League Championship Series, the episode was rescheduled to air on November 1, 2020. The episode was screened earlier on October 14, 2020, at "Paley Front Row: Simpsons Treehouse of Horror", a panel discussion put on by Decider, Paley Center for Media, and Fox, and in Canada on Citytv on its originally scheduled airdate of October 18, 2020. Cultural