Treehouse of Horror XXXI

On Election Day, Marge calls Homer and tells him to get to Springfield Elementary to vote. At the school, Homer quickly decides everyone he wants to vote for, except for who he wants to be President. Lisa enters the booth and tries to get Homer to remember everything bad about the previous four years, but Homer remembers nothing. After reading fifty things that Donald Trump did as President, Homer finally decides who to vote for. However, it turns out Homer just dreamed of voting. On inauguration day, Springfield is in chaos. Then, the Four Horsemen of the Apocalypse fly in the sky holding flags, one with the title of the episode.

Before donating his toys to charity, Bart decides to torture them, not realizing that they have feelings. Later, Marge gives him a Radioactive Man toy which Bart puts in a microwave, causing it to melt. The rest of the toys decide to seek revenge against Bart, so they kill him and turn him into a toy, greatly distressing his family.

Marge calls Homer to tell him to bring home the Halloween candy, but he ate it all. Homer searches the Nuclear Power Plant for candy and finds what he thinks is a vending machine. When he tries to put a quarter in it, it explodes. After waking up, Homer realizes that versions of him from the Multiverse have appeared. The Homers become friends and spend 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.

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.

A clip from the episode was shown during The Simpsons panel at Comic-con @ Home.[4] An extended clip was released during an interview with showrunner Al Jean.[5] 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 1996.[6] 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.[7] Ben Mankiewicz appears in the episode as himself.[1]

On 2020, Fox released 13 promotional pictures from the episode.[8] The episode was originally scheduled to air on October 18, 2020,[9] however, due to being preempted by game seven of the 2020 National League Championship Series,[10] the episode was rescheduled to air on November 1, 2020.[1] 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.[11]

In the United States, the episode was watched live by 4.93 million viewers.[16]

Tony Sokol with Den of Geek said, "The Simpsons season 32 has been offering consistently satisfying episodes of straight and subversive humor. 'Treehouse of Horror XXXI' is the best of the season so far, but the Treehouses are always season highlights, and more reliably than Christmas episodes. No character is safe on Halloween. You can kill Gil as many times as you like. The Simpsons always packs a devilishly delicious trick or treat bag, with nothing so frightening as razor-blade-concealing apples, or anything else remotely nutritious. The opening segment is a political thriller, but the segments themselves are classic comedy." He also gave the episode four and a half out of five stars.[17]