As the Phase Four teaser all but screamed, the Fantastic Four are slated to arrive in the Marvel Cinematic Universe sometime in the next few years. The specifics of their arrival -- at least as they currently stand -- are one of the most closely guarded secrets in Hollywood and could go in any number of directions. One fan theory builds upon what people already know about the MCU to create a surprisingly convincing option: that Hank Pym inadvertently created the quartet back in the 1980s.
Introduced in 1961, the Fantastic Four were originally given their powers via cosmic radiation during an unauthorized rocket launch. It was very much in keeping with the zeitgeist at the time, with the Mercury Program in full swing and the Space Race between the U.S. and the Soviet Union well underway. Ant-Man and the Wasp deliberately tapped into that feeling with its opening sequence, in which Pym and Janet Van Dyne struggle to stop a rogue missile. Though set in the 1980s, it carries much the same vibes, both with its old school rocket-based threat and in Janet's loss to the Quantum Realm, which has the sense that -- as with Reed Richards' flight -- something went terribly wrong.
That's where the Reddit theory picks up the conceptual thread. User jbl031806 speculates that Reed Richards was a scientist working for Pym Technologies whom Hank tasked with entering the Quantum Realm to find his wife. Reed does so with the assistance of Ben Grimm, plus Sue and Johnny Storm. They get lost in the Quantum Realm, possibly being sucked into a Time Vortex until they pop back out in the present-day MCU, presumably with their various powers given to them by their extended exposure to the energies there. That would make their creation an extension of Janet's tragedy and an accident on Hank's conscience.
The theory has little direct evidence to back it up, but with few solid signs of what the MCU has in store for the Fantastic Four, that's to be expected. Circumstantial evidence, however, gives it more of a backbone. Ant-Man and the Wasp: Quantumania is currently scheduled for release on July 28, 2023, almost the end of Phase Four. If their MCU origin story involves the Quantum Realm, that would provide an easy reason to introduce the Fantastic Four there. They could then arrive in a post-credits scene or even as part of the film's main story, which could set them up for a solo film to complete Phase Four. It could also further justify the inclusion of Kang the Conqueror, whom Loki Season 1, Episode 6, "For All Time. Always." set up as a major villain in upcoming MCU projects.
More importantly, it would provide an origin story for the Fantastic Four that breaks from previous versions, yet still remains true to the characters. It gets around simply rehashing the same origin story revealed in the previous Fantastic Four movies, the last of which was largely regarded as a misfire. The MCU's Spider-Man movies did something similar when they skipped a third go at Uncle Ben's death. The Fantastic Four can easily do something similar with their origins, and the Quantum Realm makes a surprisingly strong fit.
But it's the echoes of Jack Kirby where the theory really takes hold. They're on full display during the flashback scene in Ant-Man and the Wasp and create the perfect opportunity to homage the era that gave birth to the Fantastic Four without just rehashing the same old story. An accident involving Janet's disappearance would provide an easy way to deliver them in the Kirby-esque design of the Pyms' suits in Ant-Man and the Wasp, showing respect for their roots. In their own way, the characters need to be handled as carefully as the MCU handled Spider-Man. The Quantum Realm may be a surprisingly effective way to do it.