Avengers: Endgame spoilers are so heavy that Tom Holland—the Marvel Cinematic Universe's current Spider-Man and one of the most spoiler-prone actors they have—had to speak up before the official Spider-Man: Far From Home trailer and let it be known that you shouldn't even watch the trailer until you've seen Endgame. [Ed. Note: You probably shouldn't even be reading this post if you haven't seen Endgame.]
One of the main reasons for this is that the film, which [SPOILER ALERT!] is confirmed to be taking place post-Endgame, shows Peter dealing with the death of Iron Man. The reason we've congregated today is for a bit of intel that Nick Fury gives Peter about the Marvel Cinematic Universe: "Beck," Fury says, talking about Quentin Beck, a.k.a. Mysterio (played by Jake Gyllenhaal), to whom Spider-Man is introduced formally in this trailer, "is from Earth, just not ours. The snap"—Thanos' Infinity Gauntlet Snap at the end of Avengers: Infinity War, which is known officially as "The Decimation"—"tore a hole in our dimension."
"You're saying there's a multiverse?" Peter asks. And, quite simply, yes, the MCU is now a multiverse...apparently.
Comic book fans know exactly what time it is, even if they've just recently gotten into comic books. The multiverse theory is relatively simple: The majority of Marvel's comic books take place in one particular universe (Earth-616, for those counting), but multiple parallel universes exist right beside it. For example, there might be a Spider-Man in the "main" Marvel universe, but other Earths have their own Spider-Men/Women, like you saw in Spider-Man: Into the Spider-Verse. The Marvel Comics universe recently had its multiverse collide in the 2015 Secret Wars mega event, which essentially brought the best characters from the separate universes into one unified Marvel Universe. What Nick Fury is hinting at is that, essentially, whatever tear Thanos' Snap ripped in the multiverse is going to wreak havoc on our Earth, and this will more than likely play out with Mysterio having to help battle whatever monstrous villains emerge on this side of the multiverse.
Does this hint at the MCU (will we need to start calling this the Marvel Cinematic Multiverse now?) having its own Secret Wars-esque event down the line? It's quite possible. The problems with rips in the multiverse could have a number of deeper ramifications. For example, the Avengers [SPOILER ALERT!] got rid of our Thanos problem, murking him twice in Endgame. Imagine if some other Earth's Thanos has collected their Infinity Stones and escapes to our Earth to begin the whole cycle again. Or if—similar to Into the Spider-Verse—someone finds a way to hop to multiple dimensions in search of one particular goal, they could end up corrupting everything they come in contact with. This tear could have disastrous results.
One has to wonder, though: Why was this information not mentioned at all during the three-hour Engdame, which spanned something like five years in MCU time? Nick Fury shows up at Tony Stark's funeral and doesn't let (this) EARTH'S MIGHTIEST HEROES know that there's a massive problem that's been baking ever since Thor mistakenly didn't go for the head? [Ed Note: Could this be what Captain Marvel was referring to repeatedly in Endgame about having to handle issues throughout the universes? Could those problems have been species from outside of the MCU invading other planets?] And while we're asking questions, are we even sure it was Thanos' Snap that caused this tear? What about a) Loki 2012 dashing off with the Tesseract, or b) Captain America living a whole-ass life with Peggy Carter and growing old? The Ancient One explained to Bruce Banner that if anyone removed a stone from one timeline, they'd create a branch off of that that could be detrimental. They had a whole mystical graph for it on-screen. Now, sure, Cap delivered the stones they used back to their rightful places, but not everything was left the same. Loki's escape with the Tesseract is surely a setup for his Disney+ series, but you'd think that would be a bigger deal, universally, right? Hell, you'd think the Decimation of the 2014 version of Thanos and his crew in 2023 would have much bigger consequences, right? Maybe those are factors in this multiverse tear that Nick Fury spoke of.
Maybe Thanos' Snap fucked everything up deeper than we realized. Or maybe the efforts the Avengers made to repair their world, while successful, did more harm than good.