The Simpsons has run for over 30 years, and many of its most well-known sequences and episodes have entered the pop culture lexicon. One of the most infamous turns the series ever took was with a storyline that bridged two seasons and pushed the show into an unexpected direction: a genuine mystery.
"Who Shot Mr. Burns?" came at the height of The Simpsons' popularity in Season 6, and the revelation of the true culprit was a tightly guarded secret. It was such a big deal, in fact, that some of the show's higher-ups went to extraordinary lengths to hide the truth from most of the people working on the production.
"Who Shot Mr. Burns?" was a two-episode story arc. Serving as the finale of Season 6 and the premiere of Season 7, the plot focused on Mr. Burns enraging Springfield. Having caused misery for almost the entire town with the glee of a Batman villain, it came as no surprise when he was shot after a tense meeting at City Hall. The identity of who shot Mr. Burns was a hotly debated topic, with an official contest for fans to try and guess who pulled the trigger. The second part revealed it was Maggie Simpson who did the deed.
While he was literally trying to steal candy from a baby -- a desire he'd earlier mentioned to his longtime assistant Mr. Smithers -- Burns' gun fell into Maggie's hand and she pulled the trigger. It was one of the show's most surprising plot twists, at least until Season 33.
This decision was kept largely secret, even from people working on the show. Animator David Silverman was originally the lone animator who knew the truth about Maggie while Part 1 director Wes Archer didn't know the plot twist until the end of production, according to the DVD commentary for the episodes. The Simpsons voice actors didn't perform a table read of the episode's third act, leaving them largely in the dark as well.
To further hide the truth, then-showrunner David Mirkin wrote multiple alternate endings so no one would be sure if any potential leaks were valid. Harry Shearer, who plays Mr. Burns, recorded dialogue specifically for these scenes.
Some of the other conclusions were fully animated, with different animators only given small sections to work on. These alternate takes revealed the guilty party to be Moe, Apu, Barney, or Santa's Little Helper. Even guest star Tito Puente was shown attacking Mr. Burns! Puente, Moe and Barney were all presented as likely suspects in Part 2, but Moe and Puente proved their innocence during the course of the episode. Barney had been considered an early pick for the real shooter, as discussed by Mashable. Yet another false resolution ignored earlier events and positioned Smithers as the shooter.
All of these diversions were largely successful, with the actual ending coming as a huge surprise to audiences -- no one who entered Fox's contest got the answer right.
However, these brief red herrings saw the light of day three months later. The Simpsons was contractually obligated at the time to produce clip shows on occasion, including Season 7's "The Simpsons 138th Episode Spectacular." Framed as a behind-the-scenes look at the production of the show hosted by Troy McClure, the episode allowed the creators to poke fun at themselves. They showcased different takes and jokes that had been cut from previous installments, including the alternate endings, giving fans the chance to finally see the product of months of intense secrecy. Whether another Season 7 episode spinoff or more behind-the-scenes parodies like this will be released remains to be seen.