From She-Hulk smashing her way through court to Namor declaring war on Wakanda to a werewolf running around causing chaos, there's a lot happening in the Marvel Cinematic Universe. So where exactly does "Quantumania" fit in?
Well, the third installment of the "Ant-Man" series picks up after the end of the Infinity Saga, but it's still grappling with everything that went down in Phase 3. In the previous Ant-installment, "Ant-Man and the Wasp," Scott, Hope, and Hank learned that Janet van Dyne was actually alive and trapped in the Quantum Realm, prompting the Ant-Family to visit the world between worlds to pull her out. After a successful mission, it was Scott Lang's turn to get trapped inside, thanks to Thanos getting his hands on the Infinity Stones in "Infinity War" and snapping the rest of Scott's crew out of existence, leaving him stuck in limbo.
After years trapped inside, Scott used his knowledge of the Quantum Realm in "Avengers: Endgame" to help Earth's Mightiest Heroes harness the power of time travel, allowing them to visit the past, retrieve the Infinity Stones, and undo Thanos' murderous snap. Of course, during his time away, Cassie Lang grew up quite a bit, meaning Scott found himself with a teenage daughter upon returning to the world.
However, the events of the "Ant-Man" series aren't the only ones critical to understanding "Quantumania." As it turns out, the events of "Loki" are pretty important as well. In Season 1 of the Disney+ series, the titular god of mischief and Loki variant Sylvie plan on bringing down the Time Variance Authority, the organization in charge of maintaining the Sacred Timeline. Their quest eventually brings them to He Who Remains, a god-like figure who ended a multiversal war waged by his own variants by coalescing all the disparate timelines and worlds into one.
Unfortunately for the MCU, when an enraged Sylvie — looking for vengeance — kills He Who Remains, she disrupts the Sacred Timeline and allows for the arrival of his most dangerous variant: Kang the Conqueror. With the various Kang variants playing huge roles in "Quantumania," "Loki" Season 2, and "Avengers: Kang Dynasty," the events of "Quantumania" are pretty crucial to the next saga of the MCU.
