In the past year, the Marvel Cinematic Universe has opened up in a big way — and not just in terms of the introduction of new heroes and new stories. The past year has seen the idea of the multiverse take center stage in the MCU with the concept of other realities being teased in WandaVision, variants being introduced in Loki, a full-on breach of worlds in Spider-Man: No Way Home, and now an outright multiverse hopping adventure in Doctor Strange in the Multiverse of Madness. In fact, according to Marvel Studios boss Kevin Feige, Loki actually set up the multiverse for both No Way Home and Multiverse of Madness making the whole arc one that's very connected. But how exactly does that work? Let's break it down.
Warning: because there will be discussion of the multiverse in terms of how it pertains to Doctor Strange in the Multiverse of Madness, there will be major spoilers for the film beyond this point. If you don't want to know, do not read past this point.
In Multiverse of Madness, it's revealed that there are seemingly countless different realities — we even get a look at some of the weirder ones when America Chavez (Xochitl Gomez) and Doctor Strange (Benedict Cumberbatch) go tumbling through them. It's also revealed that travel between the realities in is impossible for everyone except America, which is why she's being hunted. Someone — we later learn is Wanda Maximoff (Elizabeth Olsen) — wants to take that power for themselves. We also learn that dreams aren't just dreams but snippets of the lives in other realities.
But how did we get to this version of the Multiverse? As is noted above we got a taste of it in WandaVision when, in a post-credits scene from that series, viewers see Wanda studying the Darkhold when she hears her children cry for help seemingly from another reality but there really isn't too much there in terms of the multiverse. That moment largely just serves to lead into Wanda's appearance — and villainous turn — in Doctor Strange 2. The "beginnings" of the multiverse arc in the MCU is actually Loki. The majority of the series focuses on the idea of the Sacred Timeline which sounds less like a multiverse like what we end up with in Doctor Strange 2, at least at first. It's in the Season 1 finale where things really start to come together. Loki (Tom Hiddleston) and Sylvie (Sophia Di Martino) make it to the Citadel at the End of Time and meet He Who Remains (Jonathan Majors), the creator of the Time Variance Authority (TVA). He reveals that several variants of himself discovered alternative universes and made contact with one another in the 331st century. This led to some of them trying to conquer other universes and triggered a multiversal war which was only stopped when the creature Alioth was harnessed, allowing He Who Remains to isolate the timeline — or reality — and then create the TVA to prevent branches from moving off from it, which would spark new realities and could set off another multiversal war. He gives Loki and Sylvie the choice to take over for him and keep things together or kill him and end the singular timeline/reality. Sylvie chucks Loki back to TVA headquarters, kills He Who Remains, and a multiverse of timelines is unleashed.
That act sets the stage for two things: the myriad of worlds in Doctor Strange in the Multiverse of Madness. From what Feige said at the premiere of Doctor Strange in the Multiverse of Madness, it sounds like all of those branching timelines at the TVA is just one representation of the Multiverse and that because He Who Remains wasn't around to maintain control of things, that's why Strange's spell went wrong in Spider-Man: No Way Home.
"You know, there's always a method to the madness even at the multiverse and to the Marvel.com fans who know that Loki and Sylvie did something at the end of that series that sort of allowed all of this to be possible," Feige said. "He Who Remains is gone and that allowed a spell to go wrong in Spider-Man: No Way Home, which leads to the entire multiverse going quite mad."
So, there you have it. Long before Loki there was a multiverse but He Who Remains ended the Multiversal War and kept it all at bay by using his TVA to maintain one master universe/timeline — The Sacred Timeline. Loki and Sylvie sort of threw a wrench in that in their pursuit of the truth and when Sylvie killed He Who Remains, all hell broke loose, unleashing the multiverse once again, thus setting the stage for Doctor Strange 2 and, as a bonus, because no one was controlling things anymore, that No Way Home spell was allowed to go awry giving Strange — and viewers — their first taste of just how big reality is. Now, whether that makes sense… well. That's a thought for a different day.
Doctor Strange in the Multiverse of Madness is now playing in theaters. Loki and WandaVision are now streaming on Disney+.