Edgar Wright's version of Ant-Man didn't originally include the Quantum Realm. The 2015 Marvel Cinematic Universe starring Paul Rudd went through one of the longest development cycles of any Marvel Studios movie up to this point. Baby Driver director Edgar Wright was originally attached to make the movie about the smallest MCU hero, but creative differences between him and Marvel led to him leaving the project. Although many fans remain interested in what could have been, Peyton Reed proved to be a suitable replacement and helped bring Ant-Man to life with a few new twists.

The story of Ant-Man followed Rudd's Scott Lang becoming the size-changing hero after getting out of prison and stealing Hank Pym's Ant-Man suit. This was all part of Pym's plan, though, as he needed someone to help him take down Darren Cross, who recreated the Pym Particle technology to create the Yellowjacket suits. It all led to Yellowjacket and Ant-Man fighting, with Lang forced to go subatomic to defeat him. He was temporarily lost inside Marvel's dangerous Quantum Realm before figuring out how to grow big again and escape to a place where time and space work differently.

Related: Why Edgar Wright Didn't Direct Ant-Man

The Quantum Realm plays an important role in Ant-Man's story and became an even more vital part of the MCU as the universe progressed. However, it turns out that the Quantum Realm wasn't part of the original version of the film. As part of The Story of Marvel Studios: The Making of the Marvel Cinematic Universe, it has been revealed that the addition of the Quantum Realm was something Paul Rudd and Adam McKay brought to Ant-Man. Rudd and McKay began working on the screenplay after Wright and co-writer Joe Cornish left the project, meaning Wright's Ant-Man had no mention of the Quantum Realm.

The Quantum Realm

It is somewhat surprising to learn that such a crucial part of Ant-Man and the MCU's future timeline wasn't originally part of the movie. However, this is another reminder of how different Edgar Wright's version of the movie would've been. A lot of the bones of Wright's movie are still in Ant-Man based on the short turnaround from when he left and when the movie started production, but it is clear that plenty of other changes occurred. The addition of the Quantum Realm is just the latest example of this and one of the aspects of the movie that wouldn't be included if Wright remained on board.

Considering how important the Quantum Realm became in the MCU, it is fascinating to consider what would've happened had Ant-Man never introduced it. There's the chance a sequel or other property would've made it part of the MCU canon, but Marvel also might have never used it. In that case, Avengers: Endgame's time travel plot would have to be completely reinvented. Tony Stark could've found another way to travel through time perhaps, or maybe the movie would've relied on magic to make this possible. Otherwise, it is quite possible that the Infinity Saga's conclusion would feature an entirely different setup, and all because Ant-Man never used the Quantum Realm.

More: Loki's TVA Is Ant-Man's Secret Quantum Realm City - Theory Explained

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