Fallout season 2's premiere, "The Innovator," introduces a new Vault to the show, but there's more to the abandoned facility than initially meets the eye. Because the Amazon project shares a continuity with the Bethesda games, those who've never engaged with the source material can find themselves wondering what's original to the show and what already existed within the franchise canon. Vault 24 is a little bit of a strange case in that both things are sort of true.
For the most part, the Fallout show is written to make perfect sense without playing the games. Making it necessary to explore the Wasteland for hours and hours on end before the show can be closely followed would drastically restrict its appeal. That said, those who have played the games are treated to an almost endless stream of Easter eggs and references to the interactive adventures. For example, Mr. Robert House (Justin Theroux) and his introduction in season 2 will be cause for those who loved Fallout before the show existed to point at the screen and smile. Vault 24 may also evoke a similar reaction for some.
FULL SPOILERS for Fallout season 2, episode 1, "The Innovator" below.
"The Innovator" fully canonizes Vault 24 after only being a vague concept in Fallout: New Vegas
Because of the vaults' numbering system, it's only logical that Vault 24 would exist within the world of Fallout. It wouldn't really make sense if Vault-Tec simply skipped 24. That said, it barely had a role in the games. Instead, the only evidence of its existence is a Vault 24 jumpsuit that was originally intended to be available in 2010's Fallout: New Vegas. The jumpsuit was ultimately nixed from the game, but it is still buried in the code and can be extracted by the technically-minded.
This started speculation among the gaming community about Vault 24 that has been ongoing ever since. It's become something of a digital urban legend. Thankfully, the Fallout season 2 premiere has provided the long-awaited answer to where the heck Vault 24 is and what kind of twisted experiments had been going on inside. It's also revealed to be right near a Starlight Drive-In movie theatre. The only other Starlight Drive-In was in Fallout 4, which was set in the Boston area. So this Easter egg suggests these drive-ins were part of a larger franchise.
The Vault 24 lore introduced in "The Innovator" is completely original. Fallout: New Vegas lead designer Josh Sawyer addressed the missing Vault on Tumblr back in 2019, and when asked if there was ever any Vault 24 content planned beyond the jumpsuit, he said: "I don’t believe so. I think we may have generated a few additional vault suits from vaults that we never intended to be in the game, but I can’t remember why." So, the show's writers took a tiny germ of an idea from Fallout: New Vegas' code and allowed it to grow and flourish into the Vault 24 we all saw onscreen in "The Innovator." Pretty cool.
The experiments on Vault 24's inhabitants explained
Ella Purnell's Lucy MacLean grew up in Vault 33, which was a bit of an outlier as its inhabitants weren't directly experimented upon — at least not in any way they noticed. Most of the other Vault-Tec facilities that sheltered people weren't quite so wholesome, as Lucy has started to discover since leaving the relative safety of Vault 33. Still, Vault 24 is a notable outlier. Lucy discovers that those in Vault 24 were Americans being brainwashed to become communists.
The experiments largely appear to have failed. While all the inhabitants are dressed in incredibly stereotypical "communist" attire, they've also been long dead by the time of Lucy's arrival. It also appears to be the brainwashing itself that killed them, but that's just speculation. "The Innovator" doesn't explain why Vault-Tec was trying to put Vault 24 through this kind of politically-fuelled transformation, as that'll probably be one of the bigger mysteries woven through Fallout season 2.
However, Vault 24 appears to be a testing ground for the Brain-Computer Interface Chip, which is revealed at the start of season 2 to be a mind-control device developed by Mr. House. So, maybe Vault-Tec is trying to push the piece of tech to its limits by forcing the Americans to the furthest opposite that Vault-Tec can comprehend: communism. If they can pull that off, they probably think the Interface can do anything.
Fallout's place on the franchise timeline protects the games from the wild Vault 24 reveal
The Amazon show is set after all the current Fallout games. Because of this, while it does need to keep a watchful eye on the canon at large, the show has no responsibility to shape itself to events that are yet to come. If anything, the show is going to serve as the framework for future Fallout games, as confirmed by Fallout producer Todd Howard during an interview with the BBC: "Fallout 5 will be existing in a world where the stories and events of the show happened or are happening."
So, even though the brainwashing experiments appear to have failed in Fallout season 2, there's nothing stopping the data that was gathered from being used to further the research. If the show were taking place more toward the middle of the Fallout timeline, it would be more obvious that any attempts to further the research had also failed. If they had been a success, then that surely would have factored into later games. As it stands, the Fallout show has simply retroactively confirmed that Vault 24 has been filled with wannabe-communist skeletons the whole time, even if the player hasn't been able to confirm that in the games.
Fallout season 2 is streaming now on Prime Video, with new episodes premiering on Wednesdays.