It's been promised that the as-yet-untitled Avengers 4 will change the Marvel Cinematic Universe forever. But what does that mean? As far as we know (and that is, technically, very little), Avengers 4 will be a direct follow-up to the Avengers: Infinity War fallout in which Thanos killed half the universe, including half of our heroes.
As fans prepare for Avengers 4, the internet has glommed on to every tidbit of information made officially (and unofficially) available to it by Marvel. Fan theories have, naturally, spawned from those tidbits.
MCU boss and President of Marvel Studios Kevin Feige told Vanity Fair: "There will be two distinct periods: everything before Untitled Avengers in May '19, and everything after. We're building it that way because it's good storytelling, because it's a good differentiator of how to continue to evolve and to grow. I know it will not be in ways people are expecting."
Marvel screenwriters Christopher Markus and Stephen McFeely also told The Hollywood Reporter that Captain America and Black Widow will feature much more heavily in Avengers 4, which, technically, makes a lot of sense, seeing as we lost half our heroes in Infinity War. There are only so many options now.
Here are nine Avengers 4 fan theories that are simultaneously insane and totally plausible.
We'll start out with what's probably the most likely of these theories to come true. Behind-the-scenes photos have shown MCU actors recreating scenes from previous films — specifically, 2012's The Avengers.
These photos show Chris Hemsworth in his Avengers-era Thor armor and wig, a spangly Chris Evans joined by Mark Ruffalo, Robert Downey Jr., and, most importantly, Paul Rudd in his Ant-Man suit, and a Tom Hiddleston stunt double in full Loki gear. These images have all prompted fans to think the majority of Avengers 4's plot will center around Scott Lang, aka Ant-Man, traveling through time using the Quantum Realm (which he's trapped in as of the end of 2018's Ant-Man and the Wasp). Time travel is not at all unheard of in Marvel's comics (or in the MCU, technically, if you take 2016's Doctor Strange into account), so introducing it to the big screen wouldn't be too big a deal.
Maybe this is the outcome Doctor Strange (Benedict Cumberbatch) saw in which the Avengers win. It's all thanks to the unlikeliest and most recent of MCU heroes, Ant-Man.
Plus, there's that rumor that 16-year-old actress Emma Fuhrmann has been cast as an older Cassie Lang, previously played by the suitably adorable 10-year-old Abby Ryder Fortson, for Avengers 4. If Cassie's dad is the one doing the time traveling, it'd make sense that he interacts with a teen version of his beloved daughter.
THE QUANTUM REALM WILL FIX EVERYTHING
Any theory involving the Quantum Realm is usually tied to that aforementioned time-travel thing. The Quantum Realm, which has only been utilized in the MCU thus far in Ant-Man (2015) and Ant-Man and the Wasp (2018), is an area that exists outside the laws of time and space. Now that Scott Lang's Ant-Man (Rudd) is trapped inside the Quantum Realm, we can assume the Quantum Realm will play a role in the next film Scott Lang appears in. That movie just so happens to be Avengers 4.
But what can the Quantum Realm do? In Marvel's comics, the Quantum Realm is commonly called the "Microverse," and, in some instances, is partially guarded by a group of ethereal glowing beings called Time Travelers. These Time Travelers can see possible futures and outcomes and sometimes loan their powers out to others (again, we return to the time-travel theory). Whether Scott will encounter the never-before-mentioned-in-the-MCU Time Travelers is debatable, and while Scott borrowing the Time Travelers' powers would be a little too convenient, it seems likely. Because, again, time travel really does seem likely.
THANOS' VICTIMS AREN'T DEAD, THEY'RE JUST IN AN ALTERNATE UNIVERSE
Jumping off all the time travel and Quantum Realm theories, "alternate universe" theories provide a bit of an, uh, alternative to all those leaked behind-the-scenes photos we've been seeing.
Some fans have suggested that rather than the Battle of New York and SHIELD Helicarrier scenes being the results of Scott Lang time-traveling through the MCU, we'll actually see those scenes played out in an alternate universe. That would provide an explanation for why the setup for the scenes seem a bit off and why Scott is there — instead of traveling back in time to join the Avengers, he actually just jumped over to a parallel universe via the Quantum Realm.
The outcome of those battles and scenes in these supposed alternate universes is precarious, but alternate universes are a comics staple. Introducing new universes to Marvel's onscreen blockbusters would definitely play into Feige's insistence that everything will change post-Avengers 4. It's a move that would open up entirely unexplored possibilities and add that much more to an already packed roster of multibillion-dollar movies.
THE LIFE AND DEATH (AND REBIRTH) OF CAPTAIN AMERICA
If you're an MCU fan who's spent any time on the internet in the past five or so years, you've read plenty of stories speculating on when Steve Rogers' time as Captain America will come to an end. Actor Chris Evans has portrayed Cap since Captain America: The First Avenger (2011), the character's first onscreen MCU appearance, and has long hinted at wanting to leave the shield behind for other acting (and directing) opportunities.
These speculations always tie in to Marvel's infamously expansive contracts; Evans fulfilled his original six-film contract as of Infinity War but signed on to, supposedly, complete Cap's story in Avengers 4. He's changed his tune a bit recently, as well, saying he's down for whatever direction Marvel decides to take the Star-Spangled Man with a Plan.
And if that direction is toward the grave? Well, we have Bucky Barnes (Sebastian Stan) and Sam Wilson (Anthony Mackie), both of whom have taken up the Cap mantle in Marvel's comics, standing by.
But if Steve Rogers dies in Avengers 4, what will that sacrifice be for? Some anticipate Steve dying to protect Tony Stark as a way to truly settle the beef between them. Some think he'll die saving his longtime best friend and previously brainwashed buddy Bucky, which will prompt Bucky to take over as Cap. No matter what, we know it would be a suitably heroic and heartbreaking end, with lots of tears involved. We're already getting choked up just thinking about it.
SHURI MADE A COPY OF VISION (AND THE MIND STONE)
This theory is the biggest stretch. While Shuri (Letitia Wright) is the smartest person in the MCU, introducing another Infinity Stone to the universe seems like a good way to break said universe. But if it doesn't break the universe, it would be the ultimate tool to use in the final fight against Thanos.
Some fans have considered that Shuri might have saved a digital copy of the Mind Stone while she was working on Vision in Infinity War. And while we know that Shuri's definitely going to do all she can to save T'Challa post-snap and that if anyone can make a Mind Stone it's Shuri, there are better options.
GAMORA IS ALIVE
While most fans assume that anyone killed by Thanos' snap will make it out okay in the end, there were some heroes killed pre-snap we're just not sure about. Gamora (Zoe Saldana), Guardian of the Galaxy and Thanos' favorite daughter (read: prisoner), is one of those heroes.
The theory that Gamora is alive stems from comics lore about the Soul Stone itself. The strangest and least understood of the Infinity Stones, the Soul Stone (or, rather, the "Soul Gem" in the comics) has powers beyond that which we've seen in the MCU. Canonically, the Soul Stone is sentient and can resurrect the dead, revert beings to their original state, and has a habit of trapping its "victims" in the Soul World. Many fans assume that the flat, reflective space in which Thanos sees a young Gamora after killing her is the Soul World.
If that's all true, then it means some part of Gamora — maybe the most innocent, original part of her — is still alive and ready to spring back into action.
THANOS WILL REVERSE EVERYTHING TO BRING BACK GAMORA
Infinity War emphasized Thanos' humanity and ability to actually care for someone. That's kinda weird, right?
Sure, if he hadn't really loved Gamora, he wouldn't have been able to sacrifice her in exchange for the Soul Stone, but in the context of the film, it doesn't really make sense to try and make audiences feel bad for him. The further emphasis of his pain beyond Gamora's initial death and what felt like the Russo Brothers trying to get us to care about Thanos felt a little off. He's the villain, the ultimate villain, the one we've been waiting 10 years for.
That vague emotional depth could mean something for Avengers 4. We end Infinity War on Thanos reflecting on his achievement. What if, during that contemplation, he realizes sacrificing Gamora wasn't worth all this? Now he's alone. He's lost what little family he has. Emphasizing Thanos' humanity could be a hint that he'll reverse it all in the end. It wouldn't be that heroic of a journey for the Avengers and friends, but it would bring almost everyone back to life.
LOKI IS ALIVE
Speaking of "so-and-so isn't dead" theories, let's talk about Loki.
While many have assumed Loki's death is one of the few permanent ones of Infinity War, others disagree. Loki's faked his own death once or twice before and, being the Asgardian god of mischief, it's kind of in his repertoire to keep messing with people, no matter how good his relationship with his adopted brother seemed to be post-Thor: Ragnarok.
The facts working in favor of this theory are these: Loki points out to Thanos that he's not Asgardian but a Frost Giant and the rightful King of Jotunheim; then, when Thanos snaps his neck, Loki, oddly enough, doesn't revert to his natural Jotun state of having blue skin and red eyes. It seems that, with his magic no longer working and actively keeping his Asgardian disguise in place, Loki would turn back into a Jotun. Thus, either Loki isn't actually dead (again) or Marvel really, really messed up on some in-universe lore.
It's fair to assume, though, that if Loki faked it this time, Thor will see to it that he dies for real when he finds out.
TONY STARK, SORCERER SUPREME
Better clench up, Legolas.
Images of Tony Stark actor Robert Downey Jr. wearing Doctor Strange's Cloak of Levitation in an Infinity War featurette have raised a lot of eyebrows. While these could just be shots of Downey Jr. messing around on set (as he's wont to do), there is some precedent for Tony Stark taking over as the Sorcerer Supreme in Marvel's comics.
Brian Michael Bendis' Infamous Iron Man series has featured an elderly Tony Stark as a master of the mystic arts; Tony, scraggly beard and all, appears in a vision and gives advice to Victor Von Doom, the new Iron Man. The MCU playing out any version of this seems like a stretch. But Tony "Power Trip" Stark would be the most likely candidate of the remaining Avengers to take over as a temporary sorcerer.
Fans have theorized that this might be why Doctor Strange (Benedict Cumberbatch) gave up the Time Stone to save Tony after previously promising he wouldn't hesitate to sacrifice him. And even if Tony doesn't become the Sorcerer Supreme, we all know he'll play a vital role in the final outcome.
Avengers 4 premieres in U.S. theaters on May 3, 2019.