Major Spider-Man: Far From Home spoilers ahead. In the latest installment to the Spider-Man solo film series, we're introduced to a new character by the name Quentin Beck, later on dubbed Mysterio (Jake Gyllenhaal). The mysterious being claims to be from an alternate universe: Earth-833, as opposed to Earth-616, which is where the main Marvel movie storylines as we know them exist. Of course, he was lying — so does the MCU multiverse actually exist? While we eventually find out in the film that Beck is a vengeful former Stark Industries employee who made the whole story up, this doesn't totally dispel the possibility the theory.
In Avengers: Endgame, the Ancient One (Tilda Swinton) and Dr. Bruce Banner (Mark Ruffalo) have a whole exchange about the complications of taking the Infinity Stones from different points in time, and how the Avengers' time-traveling activities would create alternate realities. "We had to look at it in terms of the scope of what happened at the end of Endgame," Far From Home director Jon Watts explained to Fandango. "Seeing all the crazy things that they did and all the questions that raises. So we’re definitely trying to answer one of the big ones — alternate timelines. So many possibilities opened up at the end of Endgame and Peter Parker is one of the few people on the ground dealing with them."
Though Watts maintained in that interview that Earth-833 is very real, this statement was given before Far From Home premiered, and therefore may just have been an attempt to keep spoilers about the true nature of Mysterio at bay. Or maybe Earth-833 really is out there, Quentin's falsities aside.
But Watts isn't the only one who has spoken about the possible existence of an MCU multiverse. Anthony and Joseph Russo, the duo that directed Avengers: Infinity War and Endgame, teased in an interview with the Los Angeles Times that Loki (Tom Hiddleston) — who was able to escape with the space stone during Captain America's first attempt to retrieve it in Endgame — might still be alive in another universe. And as blog Den of Geek points out, aside from Loki's Disney Plus show, it's believed that Tom Hiddleston had a six-film deal with Marvel so he might be due for another film appearance yet.
And if the MCU multiverse does exist for sure, this also opens up the possibility of recreating the epic Secret Wars storyline. The Russo brothers also mentioned at a panel with Collider in November 2018 that the mega-crossover, which features the X-Men, the Fantastic Four, and the Avengers altogether, is the only way they'd be lured back into doing more superhero films. And that's definitely a possibility since the Disney-Fox merger, which means the X-Men are finally fair game in the MCU.
Still, none of these teasing remarks from the directors — and nothing from Far From Home — guarantees that the vast Marvel Comics multiverse will actually be integrated into the MCU, or when. It seems like an extraordinarily complicated undertaking, although, piecing together dizzying timelines is all part of the fun, right?