The MCU Multiverse Explained
To comic book fans, the notion that their heroes exist not just in a fictional universe but in a vast multiverse — a place in which multiple and perhaps infinite universes exist — is old news. There's a prime universe where most of the action in most of the comics takes place, but then there are timelines where things turn out differently. In Marvel Comics there's a universe where Bruce Banner becomes Spider-Man instead of Peter Parker, one where everyone in the world has superpowers, and one where all of Marvel's heroes are talking animals.
Now, with the time travel of Avengers: Endgame creating separate timelines, the notion of a multiverse existing within the Marvel Cinematic Universe is much more tangible. In fact, we already know of upcoming films and television series based on that multiverse. The upcoming Disney+ Loki series will feature a version of the character who created a separate timeline by managing to escape the Avengers' clutches before Thor could drag him to Asgard. And of course there's 2021's Doctor Strange in the Multiverse of Madness.
So what is a multiverse, how does it work, and why does it matter? More importantly, what does it mean for the future of the MCU? We haven't seen much of it yet, but based on what we've seen and what's coming, here's our best shot at the MCU multiverse explained.
How does the multiverse work?
Listen carefully to the conversation between the Ancient One and Bruce Banner in Avengers: Endgame, and it tells you just about everything you need to know about how the MCU multiverse works. The Ancient One doesn't want to give Banner the Time Stone because she fears doing so will create an alternate timeline — there will be a timeline in which the Time Stone left her care during the Battle of New York, and so would never be in Kamar-taj for Stephen Strange to use in 2016's Doctor Strange, and then another timeline where the Time Stone never left her care and events unfolded as we already know them.
Simply put: you can't change the past. If try to change the past, you create a paradox. For example, if you go back in time and stop your parents from ever meeting, then how do you exist? And if you don't exist, how do you go back in time to stop your parents from meeting? You can go on like that forever. The universe solves this paradox by creating an alternate timeline. So, if you go back in time and stop your parents from meeting, then you don't change your past, you create a splintered timeline in which your parents never meet. But the timeline in which your parents did meet and conceive you? That still exists. Both timelines coexist and run parallel to one another, like two tributaries splitting off from the same river.
Mysterio's lies mean nothing
During the lead-up to 2019's Spider-Man: Far from Home, there was a lot of conversation about whether the film confirmed the existence of an MCU multiverse. In the trailer, we learned that Quentin Beck claims to be from an alternate universe where his world was destroyed. He was supposedly in the prime MCU timeline doing what he could to stop the same thing from happening.
Of course, it turns out Quentin Beck was lying about almost everything. He wasn't from another universe and neither were the Elementals. In fact, the Elementals weren't even the Elementals — they were illusory constructs created by drones and holograms.
But it's important to remember that the fact that Mysterio wound up not being from another universe doesn't disprove the existence of the MCU's multiverse. Someone could claim to be from France — if they ultimately prove to be lying, that doesn't mean France doesn't exist. It just means, you know, they're weirdly lying about being from France.
The multiverse was confirmed much earlier than most think
The weirdest part of the back and forth about whether Mysterio's cover story confirmed the existence of an MCU multiverse was the fact that the conversation was going on at all. Three years before Far from Home's release, the MCU multiverse was confirmed without Quentin Beck's help.
In 2016's Doctor Strange, the Ancient One confirms the existence of a multiverse within the MCU when she sends Stephen Strange on his memorable trip through that multiverse. As the bedraggled Strange floats through the cosmos, the Ancient One provides a narration for his trippy journey. Among other things, she tells Strange, "This universe is only one of an infinite number. Worlds without end." In parts of his trip he's exposed to reflections of himself, presumably existing in some of those other universes. As he floats through the cosmos, she asks him, "Who are you in this vast multiverse, Mister Strange?"
So there you have it. Regardless of the home address of Quentin Beck, the MCU has a multiverse and its existence was confirmed long before Far from Home, though it's understandable why this was forgotten or ignored. Far from Home was preceded by Endgame, the first MCU film to really have anything significant to do with time travel and alternate timelines — which is probably why it was closer to the forefront of observers' minds than it might have been while watching Doctor Strange in 2016.
Steve Rogers married Peggy Carter in an alternate timeline
Steve Rogers' decision to remain in the past at the end of Avengers: Endgame is a perfect example of how the MCU multiverse works. When asked about Cap, co-director Joe Russo confirmed that when he stays in the past and marries Peggy Carter, the life Steve lives occurs in an alternate timeline. Then, at some point, Steve somehow returns to the prime MCU timeline to give his shield to Sam Wilson.
One of the big questions on fans' minds is if Cap really did accomplish his mission. Steve's job was to return all the Stones at the exact moments they were taken from the various times, thereby stopping alternate timelines from being created. But first of all, we never see Steve's quest, so we don't know if things worked as planned; second, there's a question of whether Banner's theory around bringing the Stones back is sound in the first place.
Banner tells the Ancient One that bringing the Stones back to the precise moments when they're taken, and returning them, will stop the timelines from splitting. But would it, or is it possible it would make things worse? For example, Banner takes the Time Stone. As soon as he takes the Stone, an alternate timeline has been created. Would bringing the Stone back erase the second timeline, or would it create a third?
This is why we can only hope time machines remain in the realm of fiction.
Loki escaped in an alternate timeline
Somewhere out there in the multiverse, Loki is alive. And the reason he's alive is not only what allows for his upcoming Disney+ miniseries, but it also possibly complicates things with MCU's multiverse even more.
In Endgame, Loki gets his hands on the Tesseract while Thor is trying to resuscitate Tony Stark. Once he does, he disappears in a blue cloud. A new timeline has been created — one in which Loki was never brought to Asgard to face Odin's justice after the Battle of New York. Presumably, we'll be finding out what happens to that Loki in his upcoming miniseries.
Whether Banner's theory on how to un-splinter the timeline is correct, when it comes to this specific alternate timeline, it doesn't matter. Remember: Loki's escape prevents Steve and Tony from getting the Tesseract, forcing them to go back to the '70s and get it from S.H.I.E.LD. When Cap goes back in time to return the Stones at the end of Endgame, he only has one Tesseract to return. Presumably, he's going to return it to the '70s, but that means everything that happens in Stark Tower — with Thor resuscitating Tony, Loki escaping, and Future Cap and Past Cap having a brawl — all still happened. That timeline still exists.
Thanos created an alternate timeline when he left 2014
There's one more alternate timeline that couldn't have been erased by Cap's journey to the past — the timeline in which the 2014 Thanos and his forces jump forward to 2023 and assault Avengers Compound. When Thanos captures Nebula from 2023, they reverse-engineer her Pym Particles and replace her with 2014 Nebula, allowing them to jump forward nine years.
What does that all mean? There now exists a timeline in the MCU where Thanos and all his forces disappear in 2014, never to return. As soon as the respective interstellar empires of that timeline realize he's gone, they'll probably have one huge multi-planet party that lasts a few decades.
Returning the Soul Stone to Vormir can't alter Thanos' disappearance, it can only create more divergent timelines. In a way, you could argue Tony Stark does double duty when he snaps away the Mad Titan at the end of Endgame — he wipes out Thanos from not just one, but two universes.
We'll be seeing an alternate version of the Infinity Saga in What If?
More than any other single film or television show, the upcoming animated series What If...? on Disney+ is likely to showcase more corners of the Marvel multiverse than we've ever seen.
The show is based on the Marvel comic What If dating back to 1977, which has seen multiple follow-up volumes. Each issue takes a Marvel story and shows us what would've happened if something in the story happened differently. For example, in 1963's Amazing Spider-Man #1, Spidey infiltrates the Fantastic Four's Baxter Building in the hopes of joining the team and solving his cash flow problems at the same time. Unfortunately, he learns the FF doesn't pay. So in 1977's What If #1, we get to see how things would've unfolded if Spidey had joined the team. Most issues open with the enigmatic figure the Watcher, explaining to us that the events we're about to see aren't purely hypothetical — they did happen, but it a timeline alternate to the prime Marvel Universe.
Speaking to ScreenRant, Marvel Studios President Kevin Feige explained that the first season of What If...? will deal with "everything you know about the 23 movies in the Infinity Saga and adding one twist to them and seeing how everything turns out different." Assuming the series follows the example of the comics, that means in What If...? we'll be seeing over 20 different timelines all existing within the MCU.
Could Endgame be responsible for the Multiverse of Madness
We don't know a lot yet about 2021's Doctor Strange in the Multiverse of Madness, but just from the name it seems likely we're going to be learning more about the MCU's multiverse in the Doctor Strange sequel. If any hero is equipped to explore the multiverse, it's Doctor Strange. His first film introduces the multiverse, and it's that multiverse that Strange uses the Time Stone to explore in 2018's Avengers: Infinity War.
It's possible the events of Endgame are the key to whatever is going wrong in the upcoming sequel. Endgame is the only time we've seen any kind of significant time travel in the MCU. The very phrase "Multiverse of Madness" suggests something has gone wrong with the multiverse, and if that's the case, then the time-hopping the heroes and villains of Endgame made could be the reason.
Another big hint is the upcoming Disney+ miniseries WandaVision. We don't know much more about the series than we do about the Doctor Strange sequel, but what we do know is intriguing — Elizabeth Olsen has said at least part of the series will have a 1950s setting, which hints pretty strongly at a multiverse connection.
Could the Mighty Thor be from an alternate 2013?
At the same time we heard about What If...? and Doctor Strange in the Multiverse of Madness, we learned we were going to be meeting the Mighty Thor — a.k.a. Jane Foster — in the fourth entry of the Thor franchise, Thor: Love and Thunder.
What does this have to do with the multiverse? Well, all that time-hopping in Endgame may give us the most obvious answer to the question of how Jane gets all mighty. Steve Rogers has Mjolnir with him when he goes back in time at the end of Endgame, but it isn't with him when he returns as an elderly man. Presumably, Steve would've returned the hammer to Asgard circa 2013 when he returned the Aether. If so, then that might be the answer.
For the sake of argument, assume that when Steve arrives in 2013 Asgard, he doesn't grab the first Asgardian he sees and say "Hey, I'm a time traveler! Can you tell me where Thor is?" Assume Cap simply leaves the hammer somewhere, knowing it will go to Thor as soon as the thunder god summons it, and then continues on his journey. Then assume Jane Foster comes upon the hammer wherever Steve happens to leave it. Out of curiosity, if you found yourself alone with the hammer of Thor, wouldn't you give it a shot?
Could the multiverse encompass other companies and mediums?
One possibility that's loomed since before Disney's acquisition of Fox is that Marvel characters whose film rights are still held by other studios might be narratively connected to the MCU through the multiverse. When rumors swirled that Venom might be showing up in Spider-Man: Far from Home, the multiverse was an explanation some fans clung to.
While there's been no indication that Marvel Studios plans to use the multiverse in this way, it's not out of the question. With the Fantastic Four, X-Men, and Deadpool all under the Disney umbrella, it could be there are elements of their respective Fox films that Marvel likes. If so, one way to keep them whole would be simply say the previous movies took place in an alternate timeline. The same possibility exists with Venom as well as the other Marvel properties Sony is either actively adapting or planning to adapt, like Morbius, Kraven the Hunter, and Silver Sable.
This is an idea Marvel's already used — though it was Marvel Comics instead of Marvel Studios. In the 2014 comics event Spider-Verse, versions of Spider-Man in other media were considered to be alternate universe Spider-Men. The Spider-Man from the '80s Spider-Man & His Amazing Friends cartoon, from the newspaper strip, and even from old Hostess ads Marvel's comics used to carry were all considered genuine Spider-Men from other universes. In the sequel, 2018's Spider-Geddon, the Spider-Man of that year's PS4 exclusive Spider-Man video game was one of the comic's heroes.
The MCU Multiverse is potentially a resurrection easy button
Thanos brutally murders Loki in the opening scene of 2018's Avengers: Infinity War and later — with less relish but no less intent — he hurls his adoptive daughter Gamora to her death on Vormir. Yet both Loki and Gamora show up in the 2019 follow-up Avengers: Endgame and we'll be seeing both of them again. Loki will enjoy his own solo miniseries on Disney+ while Gamora will almost definitely be back for the upcoming Guardians of the Galaxy Vol. 3. Both characters survive as part of alternate realities. Even if Captain America returned all the Infinity Stones exactly where they were meant to be, Loki's escape in NYC and Thanos' journey to the past each create splintered timelines that can't be undone by Steve Rogers.
The MCU multiverse provides a resurrection easy button for Marvel Studios' storytellers. Want to bring back Odin, the Warriors Three, and all the other Asgardians? They must exist in an alternate timeline. Want to reunite Wanda Maximoff with her speedster brother who dies in Age of Ultron? There must be a timeline where Ultron didn't kill him.
That doesn't just go for the good guys. With the multiverse more prominent in the MCU's narrative, we could see the return of any villain from as far back as Jeff Bridges' Obadiah Stane. And they might be slightly altered — marked by their different experiences on a slightly different Earth.
It opens the door for more classic Marvel stories to be adapted
While the notion of a multiverse is just now becoming important in the MCU, alternate reality stories have been a staple of comics for decades. A devoted fan of DC and/or Marvel Comics has likely read dozens of stories showing their favorite heroes in a completely different set of circumstances. Such stories used to be fairly novel, but these days you can hardly find a week's crop of new comics that doesn't include at least one or two stories featuring popular superheroes in divergent realities.
Now that the multiverse is a more prominent part of the MCU, it opens the doors for many of these stories to be seen on the big screen. One more gruesome example is the world of Marvel Zombies – in which most of the world's surviving heroes and villains are rotting zombie cannibals. We could visit the timeline of Earth X, where every last person on Earth has super powers. When the X-Men finally show up in the MCU, we could see the Age of Apocalypse, in which — in the wake of Professor X's untimely death — the villain Apocalypse rules over Earth.
In fact, speaking of "Age of" stories, we could see a more comic book-accurate version of Age of Ultron. In the comic the second Avengers movie is named after, the super-intelligent robot finally conquers the Earth and the only surviving heroes live in hunted bands among Earth's ruins.
Alternate realities could come into conflict
Alternate realities don't necessarily exist peacefully side by side, at least not in Marvel Comics.
The 2013 revamp of the Avengers comics includes a slow-burning storyline in which some of the heroes of Marvel's prime Earth face the impossible moral question of whether or not to destroy other realities in favor of their own. The heroes become aware of a series of incursions in which Earths from different realities are colliding and destroying one another. The tale culminates with 2015's Time Runs Out and finally with Secret Wars. The first issue of Secret Wars opens with a clash between the heroes of the prime Marvel Earth and the survivors of the Ultimate Earth, and finally the destruction of both. Doctor Doom remakes the multiverse in a single "Battleworld," until finally at the end of Secret Wars the multiverse is restored.
With the multiverse potentially looming large now in the MCU, something like the Avengers comics' incursion story could show up on the big screen. We already saw just the faintest glimmer of conflict in Endgame when the Ancient One initially refused to give Bruce Banner the Time Stone. There wasn't much of a physical battle between them, of course — beyond the Ancient One's separating Bruce's astral form from the Hulk's body — but it highlights the idea of heroes needing to face the difficult moral choice of whether or not to forsake one reality for the welfare of another.
Crisis may have inadvertently done the MCU a big favor
The 2019-'20 television CW crossover Crisis on Infinite Earths is a triumphant tribute to the 1985-'86 comic book crossover of the same name. Ironically, what the late Stan Lee used to called Marvel's "Distinguished Competition" may have inadvertently done the MCU a big favor.
The idea of a multiverse — of infinite alternate realities existing side by side — isn't a simple one. It's one thing to ask your audience to imagine, say, that there are different planets with different intelligent species as we see not only in superhero stories but in popular science fiction franchises like Star Wars and Star Trek. It's another to ask them to imagine there is a place where all or most of the same people exist, just slightly different. There is one Earth where the Axis powers won World War II, one Earth where the Titanic never sank, one Earth where JFK served two full terms as President and died of old age, etc.
The Arrowverse's Crisis on Infinite Earths has given audiences a picture of exactly how the MCU's multiverse could work without Marvel Studios ever having to lift a finger. It's fitting, too, considering that — while both DC and Marvel have produced some wonderful alternate reality stories over the years — it was the DC comics CW's Crisis is based on that represented the first major comic book crossover to deal with the concept of a multiverse on a grand scale.