It’s a debate Marvel fans have been having for the past two years. When Steve Rogers went back in time to live with Peggy Carter at the end of Avengers: Endgame, did he remain in the same timeline or create a new one? There have been various takes on this over time—even the people who made Endgame can’t agree on it—but it’s possible that Black Widow may have secretly confirmed the truth: Steve stayed in the main MCU timeline.
One running joke in the movie concerns Red Guardian (David Harbour) discussing his old rivalry with Captain America. In his introductory scene, he talks about a grand showdown he had with the hero back in the 1980s. When Ursa remarks that Cap was still frozen in the ice back then, Alexei breaks his wrist. Later, he quizzes Natasha (Scarlett Johansson) on if Cap ever talked about him, which a confused Nat ignores.
Most fans have taken this as Red Guardian simply inventing a past history with Captain Rogers to make himself seem more important. However, he definitely acts like he fully believes his stories. So what if he really did face Cap in the 80s and the one he fought was the Old Cap, secretly going on missions—for his S.H.I.E.L.D. co-founder wife—while his young self is still sleeping? This wild but still feasible theory was first pitched by ScreenRant.
If he traveled back to Peggy in the ’40s, Steve would’ve been in his late 60s/early 70s by the time he theoretically battled Red Guardian in the 1980s. But the super-soldier serum in his veins would’ve ensured that he was still fighting fit. His advanced age could explain how Shostakov beat him, though, assuming he’s telling the truth about that part. It’s possible that Natasha’s adopted dad encountered the time-travelling future version of his daughter’s Avengers teammate and never knew it.
As the MCU hurtles deeper into Phase 4, it feels less likely that we’re going to get a definitive answer on the ins and outs of Cap’s happy ending, so intriguing Black Widow theories like this one are all we’ve got.
