The ending to Avengers: Endgame—which we're about to spoil a little bit—left fans with several questions, many of which concern Captain America's final journey to restore the main timeline. Inquiring minds are desperate to find out how Steve Rogers accomplished his mission and what exactly he encountered along the way.
In a recent interview with Business Insider, the Russo brothers revealed that Loki plays a pivotal role in putting the puzzle together. "Loki, when he teleports away with the [Space] Stone, would create his own timeline," said Joe Russo. "It gets very complicated, but it would be impossible for [Cap] to rectify the timeline unless he found Loki. The minute that Loki does something as dramatic as take the Space Stone, he creates a branched reality."
Anthony notes that we're now "dealing with this idea of multiverses and branched realities, so there are many realities," a concept this summer's Spider-Man: Far From Home will lean into.
In Endgame Iron Man and Ant-Man were charged with retrieving the Space Stone from 2012, but ultimately lost it to Loki, who whisked himself away for the rest of the film. At the end, Steve's journey to rectify the timeline could only be accomplished by getting the stone back from Loki.
Based on this idea, it's implied that the God of Mischief's upcoming series on Disney+ may feature Captain America and the encounter that allows him to recover the Space Stone. We already know of Marvel's plans to connect the streaming service's shows to the MCU, and Tom Hiddleston is reprising his role for the series, so Cap's appearance is entirely plausible.
The Russo brothers may have set up Cap's journey to be a deeper story that continues into the future of the MCU. Anthony added, "There's a question of, how did this separate timeline Cap come to reappear in this timeline and why?"
Earlier this month, Joe said, "There’s a lot of layers built into this movie and we spent three years thinking through it, so it’s fun to talk about it and hopefully fill in holes for people so they understand what we’re thinking."