The Marvel Cinematic Universe is getting more and more confusing, thanks to the introduction of the “multiverse.” The multiverse is a concept where parallel universes co-exist with variant versions of the same characters. The concept was first introduced in the MCU in Avengers: Endgame, when the Ancient One (Tilda Swinton) explains to a time-traveling Bruce (the Hulk) Banner (Mark Ruffalo) that giving him the Time Stone could create an alternate universe, replacing her universe. Banner was on a mission to the past, with Tony (Iron Man) Stark (Robert Downey Jr.), Steve (Captain America) Rodgers (Chris Evans), and Scott (Ant-Man) Lang (Paul Rudd). Their mission would have other significant consequences for the multiverse, which led directly to the Loki series. We’ll get to that shortly. But the effects of the multiverse have – on occasion – delighted MCU fans. In 2021’s Spider-Man: No Way Home, Tom Holland’s Peter (Spider-Man) Parker came face to face with, and teamed up, with alternate Peters played by Tobey Maguire (who played the role in three films from 2002-2007) and Andrew Garfield (who spun the webs in two films from 2012-2014). It also brought back villains from those films, including Jamie Foxx’s Electro, Willem Dafoe’s Green Goblin, and Alfred Molina’s Doctor Octopus. 2022’s Doctor Strange In The Multiverse Of Madness, was not quite as popular as No Way Home. But in that film, we saw the return of Patrick Stewart’s Professor Charles Xavier from the X-Men movie franchise, Lashana Lynch’s Maria Rambeau from the 2019 Captain Marvel as a variant Captain Marvel and Hayley Atwell who played Peggy Carter as a variant Captain America. ("Captain Carter" was inspired by an episode of the animated Disney+ show, What If…? which also explores alternate timelines.) 2023’s Ant-Man and the Wasp: Quantumania also dealt with the multiverse and included Kang (Jonathan Majors), who was introduced in Loki’s first season as a character called He Who Remains. The “Multiverse Saga” will likely wrap up with 2027’s Avengers: Secret Wars, but until then, you’ll be seeing and hearing a lot about it in the upcoming MCU shows and movies. Some of them that are more earth-based (like the upcoming Daredevil and Echo series) will probably not have multiversal tie-ins. Loki season 2, however, will surely give you a headache if you’re not up to speed. You don’t need to see every MCU story to know what’s up. But here are some movies and shows you definitely should be familiar with. Minor spoiler alerts ahead. Loki season two, starring Tom Hiddleston in the lead role, will have six weekly episodes and kicks off on October 5 on Disney+.