Obvious Spoiler Warning: If you’d prefer to keep the film a mystery in the event these leaks turn out to be true, turn back now.
An anonymous source leaked several details on the highly-anticipated and yet to be officially subtitled Avengers 4, which hits theaters on April 26th, 2019. Although the leaker has not identified themselves, they have proven themselves credible in the past, leaking many plotpoints from Avengers: Infinity War that fans at the time thought to be unlikely but eventually turned out to be true.
For the most part, anyway. While the leaker did get many things right, they also were incorrect on a few points, hinting that whoever this mystery individual is, they’re probably getting their information from someone in Marvel Studios who only really gets to work with the film in its early stages. Due to Infinity War being such a massive production, its more than likely that there were many changes made to the script once filming began (Such as Drax’s famous “Why is Gamora” line, which was completely improvised).
According to the leak, “Iron Man reassembles the Avengers and decides to build his own Infinity Gauntlet to undo everything that Thanos did. They recruit Ant-Man to help them travel through time and space using the Quantum Realm to retrieve the Infinity Stones from different time periods.”
Two whole sentences into this supposed leak, and things have already gone off the deep end. First, according to the Marvel Cinematic Universe fan wiki, the Quantum Realm is “an alternate dimension only accessible through magical energy, mystical transportation using a Sling Ring, or by tremendous subatomic shrinking caused by the Pym Particles.” The quantum realm is where The Ancient One sends a young Stephen Strange in the beginning of the film Doctor Strange, and is also where Ant-Man is sent after going “Subatomic” during that film’s epic finale. The wiki goes on to mention that “in the Quantum Realm, space and time are believed to be irrelevant.”
This lines up with the leaks about the Quantum Realm, and make enough sense that it could be seen as a possibility for Avengers 4. After all, this realm has already been established as a place where time and space have no meaning, so using it for time travel wouldn’t be too much of a logical leap for the fourth Avengers film to make.
The source also mentions that Banner and Hulk will merge into “Professor Hulk”, which also lines up with this leaked Avengers 4 concept art that shows The Hulk striking a very non-savage pose and wearing a black (Possibly vibranium) jumpsuit. The Professor Hulk character is exactly what it sounds like: One of the “advanced” forms of The Hulk in Marvel Comics, this transformation has Banner’s intellect successfully in control of The Hulk’s body.
Thanos eventually discovers this time-traveling plan and uses the Time Stone in an attempt to thwart The Avengers’ plan, which is to gather up the stones and combine them in their own Infinity Gauntlet built by Tony Stark and undo Thanos’s life-ending snap.
The source also said that Thor will reconstruct Mjolnir and Captain America will wield the hammer in an attempt to hold off Thanos while the plan is completed. Captain America wielding Thor’s mighty hammer was something that was hinted to all the way back in Avengers 2 during that film’s opening scenes.
The leak concludes by adding to the death toll of the latest Avengers romp with a few more deaths, permanent this time: The leak states that Captain America will die after attempting to hold of Thanos, and also that only two of the following characters survive the film: Stark, Thor, Hulk, Hawkeye and Black Widow.
Another leak from Spider-Man: Homecoming 2 has Peter mourning the death of Tony Stark at the start of the film, hinting that Iron Man may not make it past Avengers 4.
While it doesn’t specify Hulk’s death, it does hint that he loses an arm while attempting to wield Iron Man’s constructed Infinity Gauntlet. This could be where Professor Hulk weighs into the film’s plot: The Avengers need a being powerful enough to wield the completed gauntlet, but clever enough to use it.
Or perhaps that’s not how this weighs into the plot, because maybe none of this has anything to do with Avengers 4. With leaks like these, there’s always a good chance that it’s just someone trying to take advantage of the anticipation leading up to the next Avengers film, so don’t forget to take these details with one, or two, or maybe a few dozen grains of salt.