Marvel spent the best part of a decade teasing its cinematic shared universe, before finally bringing it all together for 2012's The Avengers. After one official sequel -- Age of Ultron in 2015 -- another non-official sequel -- Civil War in 2016, and more to follow, fans have been eagerly pitching their theories to try and fill in the blanks, close-up plot holes and come up with wildly different character motivations than were canonically presented. Some Avengers fan theories draw from storylines in the comics to try and predict what will happen in future films, while others draw on events in the wider MCU to theorize how they may have affected Avengers films without viewers even noticing.
Then there are those that are just too fun to not be true -- like the popular fan theory that the real reason Stan Lee has a cameo in every Marvel movie is because he's secretly Uatu The Watcher. This theory gained so much traction that it's referenced by director James Gunn and Marvel Entertainment boss Kevin Feige in Guardians of the Galaxy: Vol. 2, which features two scenes of the industry legend sitting somewhere in deep space having a catch-up with a group of Watchers about (presumably) everything he's witnessed. If Stan isn't an actual Watcher, he's clearly on their cosmic payroll in some capacity. While these fan-favorite theories haven't been officially endorsed, they're just crazy enough to actually be plausible.
15 BLACK WIDOW WANTS CAP TO HAVE A "SUPER BABY"
One of the ongoing jokes in Winter Soldier revolves around Black Widow's interference/encouragement (depending on how you read it) with Cap's love life... or lack thereof. Throughout the film, she suggests multiple candidates, and by the time Civil War rolls around, Steve has set his eyes (and mouth) on Sharon Carter, aka Agent 13.
But, is this just workplace chatter, or does Widow have an ulterior motive -- as she so often does? One wild fan theory suggests that Natasha's prompts for Steve to finally shed his "virgin" status are actually a S.H.I.E.L.D directive, in the hope that he might pass on the Super Soldier gene without feeling like he's being coerced. It's even possible that Agent 13 could be in on the plan, too.
14 RED SKULL ISN'T DEAD AND HAS COLONIZED A HYDRA PLANET
Remember at the end of Captain America when Red Skull seemed to get eviscerated by the Tesseract's power? Well, if you watch the scene again, you'll notice that after the energy cuts through him, the beam then blasts upwards through the clouds. But, could a supervillain of his caliber really be gone for good? This fan theory says otherwise.
Based on the fact that the "Cube" is revealed later to be the Space Stone, which can, "open a doorway to the other end of space," in the words of Hawkeye in The Avengers, it's completely plausible Red Skull was teleported, not killed. And what about all his Hydra flunkies who got zapped too? Others reckon that -- based on Peter Quill being referred to as an "Earthling" and Earth as "A human planet," rather than "the" -- a Skull-led Hydra space colony could well exist somewhere out there.
13 LOKI IS SUFFERING FROM TEENAGE ANGST
From abandonment to jealousy to ego-mania, Loki has a lot of issues to work through during the events of Thor and The Avengers. But, could his temperament actually be because of hormones? One fan theory reckons that Loki should be cut some slack because he's simply "going through puberty." How is this possible? Well, Frost Giants and Asgardians appear to be immortal gods to us mere mortals, but really they just age far slower.
At the start of the MCU, Thor is already a century old in human time, but the timing of his coronation suggests he's just entering adulthood. That means Loki -- his adopted younger brother -- could be pulling attention-seeking stunts on Earth because he's still technically a teenager. Judging by the hair and melodrama, he's probably going through his emo phase.
12 THE CHITAURI INVASION WAS JUST A DISTRACTION
Unbeknownst to S.H.I.E.L.D and the newly-formed Avengers, the alien invasion at the climax of The Avengers was spearheaded by Thanos, who was colluding with Loki. Though it took a nuclear weapon to stop them, the team succeeded in repelling the invading forces. Job done. Shawarma all around! But, what if Tony and the gang were celebrating prematurely?
Based on the Chitauri's shapeshifting abilities from the comics, and the stealth tech that the Dark Elves had possession of, one theory puts forward the idea that while the Avengers were distracted fighting their army, Chitauri agents slipped through, blending in and settling into hiding places on Earth to lie in wait. They couldn't have snuck through without attracting attention, so Loki made the distraction as grand as possible. This may be moot now with the MCU's forthcoming inclusion of the Skrulls (the shapeshifting, creative forefathers of the Chitauri) in Captain Marvel, but anything remains possible!
11 ULTRON WAS REALLY PREPARING EARTH FOR THANOS
With his not-so-sunny disposition and catchphrases like, "They're doomed," Ultron's character often sounded like a tin-foil-hatted weirdo clutching a "The End Is Nigh" cardboard sign. "When the Earth starts to settle, God throws a stone at it, and believe me, he is winding up." It almost sounded like Ultra wasn't speaking generally here -- he sounded like he's got a specific doomsday event in mind.
And, according to one fan theory, maybe he did. Maybe, thanks to his programming that was focussed on searching for extraterrestrial threats, he was able to glimpse Thanos' coming through his link to the Mind Stone (which Thanos has also had contact with in the past.) Unfortunately, due to his morally-skewed thinking, his method of strengthening humanity involved killing most of it... or was that just his weird way of trying to save it?
10 THE AVENGERS AND PULP FICTION ARE IN THE SAME UNIVERSE
On the surface, this theory -- that Marvel movies could intersect with the 1994 Quentin Tarantino film -- sounds like a pretty farfetched idea, but the evidence is weirdly compelling. The most obvious connection between the two is the fact that both Nick Fury, the Avengers "Assembler," and Pulp Fiction's Jules Winnfield are played by Samuel L. Jackson.
But, the connection deepens when you realize that the Biblical quote on Nick Fury's grave at the end of Winter Soldier is the very same one his character in Pulp Fiction quotes. While this could just be a nod to the actor's resume, the crux of this theory lies in the fact that the quote -- from "Ezekiel 25:17" -- was made up by Jules. So, the only way Fury would know it is if he and Jules were secretly the same person.
9 HAWKEYE IS SPYING ON THE AVENGERS
Despite doing some solid hero-ing, Hawkeye still gets a lot of flack for being perceived as the least powerful member the of the team. And, in some ways, he is an odd fit. Not only is he without superpowers or even any weapon as advanced as Iron Man's suit, he's also really well-adjusted and maintains a normal domestic life.
This fan theory reconciles all this in a really simple way -- Hawkeye's real role is to keep tabs on the team for Nick Fury. We know Fury is paranoid enough to do that because he went so far as to install a fake neighbor next door to Steve in Winter Soldier. We also know that Hawkeye and Fury are close because Fury helped hide his family from S.H.I.E.L.D. And, it also explains how Fury is magically able to appear wherever the Avengers are.
8 THE NUKE WAS MEANT TO KILL THE AVENGERS
In The Avengers, the World Council decides that desperate times call for nuclear arms, and launch one straight at Manhattan, which the Chitauri army was descending on. This is a very rash decision considering the obvious cost to both civilian life and Earth's Mightiest Heroes, and one that they had to fight Nick Fury on.
One theory speculates that the reason the World Council were so trigger-happy was that they may have been infiltrated by Hydra, and saw the battle as an early opportunity to assassinate the Avengers under the guise of collateral damage. Of course, this comes with a healthy dollop of speculation, as you'd then have to assume that at least some of them secretly did know about Project Insight in Winter Soldier.
7 PROJECT INSIGHT WAS SUCCESSFUL
Outside of the films, you could chalk up the reduced Avengers membership in the MCU compared to the comics to purely logistical and financial reasons. But, is there actually a more sinister explanation for this in-story? One fan theory suggests that the reason for this is because Project Insight -- Armin Zola's algorithm that seeks out people who could threaten Hydra -- was been in beta-testing mode for decades before wider implementation.
That would explain how Hydra already knew about people like Doctor Strange, and why the X-Men are missing. Also, it's why the Avengers roster seems to only be made up of unpredictable elements: an extraterrestrial, a billionaire who had a moral epiphany, a time-traveling soldier, and a big, green monster who should have been killed by the accident that created him.
6 HEIMDALL HAS THE SOUL STONE
Five Infinity Stones -- Space, Reality, Power, Time and Mind -- have surfaced across the corners of the MCU so far, but the sixth stone, Soul, is still missing. Or is it? There's quite a convincing fan theory floating around the Internet that the final stone has been right in front of our faces since Thor, in the possession of Asgard's gatekeeper, Heimdall.
The first clue is that Heimdall's power could potentially rival Odin's. "You have great power Heimdall," Loki remarks in Thor. "Did Odin ever fear you?" Heimdall tells him "no," but only because he is "sworn to obey him." Another hint is dropped in The Dark World, in which Heimdall tells Thor that he can see "ten trillion souls." Not "people," specifically souls. Perhaps he meant this literally.
5 LOKI WON IN THE AVENGERS
Loki appeared to suffer a devastating and humiliating defeat in the first Avengers movie, one far beneath such a smart and creative mind as his. But, considering what he goes on to achieve in Thor 2, maybe this loss wasn't actually a loss at all. Maybe it was a calculated one. According to one radical fan theory, Loki's plan was actually a Xanatos Gambit.
This Gambit is a plan that cannot fail because, whatever the outcome, its creator wins. Think about it -- if the Chitauri invasion succeeds, he gets to rule Earth. But, if it loses, Loki is able to achieve his life-long dream of ruling Asgard. Using his exceptional deception skills, he convinced everyone that Earth was his prize. Really, Loki wanted to lose all along because taking Odin's job affords him a much more cosmically powerful position in the universe.
4 ZEMO WANTED TO RESTART THE SUPER SOLDIER PROGRAM
Like most wild fan theories, this one stems from one line. Towards the end of Civil War, Everett Ross gloats to Zemo. "How does it feel? To spend all that time [...] and to see it fail so spectacularly?" To which Zemo cooly replies, "Did it?" The obvious point of reference here is that his plan to rupture the Avengers worked. However, there's an interesting fan theory that claims otherwise.
Could Zemo have also hoped to lead the US military to the Winter Soldier facility along with Steve, Tony and Bucky? Maybe the other "empire" he hopes to destroy "from within" is the entire US government, by destabilizing the country with a new generation of hard-to-control superpowered people. People such as General Ross, who becomes the destructive Red Hulk in the comics, and suddenly returns to the forefront of the Avengers world in Civil War.
3 COULSON IS IMMORTAL
One of the many adorable Phil Coulson traits is his fanboy adoration of Captain America. This is played-off as a general love of vintage things -- hence his retro car in Agents of S.H.I.E.L.D and his collectible Captain America cards. But, what if he actually has those cards because he bought them when they were released... in the 1940s? This fan theory was sparked by a scene in Captain America featuring a boy with a DIY Captain America shield.
Theorists think that that kid might be a young Phil, who will go onto to become the next subject in the Super Soldier program -- inspired by his hero. After all, the program was a success, and, as we saw in Incredible Hulk, attempts to continue it kept happening. Granted, he doesn't quite have Steve's helicopter-anchoring arms, but he still might have the serum's fully-perfected regenerative capabilities.
2 SCARLET WITCH IS (STILL) A VILLAIN
Scarlet Witch was introduced as a villain in Age of Ultron, so is it really so hard to imagine that -- despite becoming #TeamAvengers -- she never really truly gave up her villainous ways? The death of her brother motivated her to grief-stricken-ly murder Ultron in brutal fashion. Could she be playing the long-game to get similar vengeance on the Avengers for the death of her parents?
This theory goes so far as to assert that Scarlet Witch planted the idea that Tony should create Ultron after telepathically scaring him half to death, hoping Ultron would see the team as a threat to be eradicated. Quicksilver's death could have been an unexpected hiccup. Given her obvious mental instability (true to the comics) it's possible her resulting guilty conscious is evidence of a woman having an identity crisis.
1 STAN LEE: A MAN RUINED BY SUPERHEROES
The most popular theory about Stan Lee's legendary Marvel movie cameos claims his ubiquity is down to him secretly being Uatu The Watcher. But, what if they're nowhere near that deliberate? What if Stan is just always in the wrong place at the wrong time? This epic theory strings them into a narrative, beginning with Stan Lee Sr. failing to meet Steve Rogers at an awards ceremony in Captain America.
In Agent Carter, Stan Sr. goes missing, leaving his son, Stan Lee Jr. to become famous for stopping a robbery in the Netflix/Marvel-verse; mistaken for Hugh Hefner and then Larry King by Tony Stark; poisoned in Incredible Hulk; has his truck destroyed during Thor; and can only watch in dismay as New York is wrecked in The Avengers after returning home. "Superheroes in New York? Give me a break..."
Which of these mind-blowing fan theories do you think is the most plausible? Let us know in the comments!