On Friday morning, Marvel released the highly-anticipated trailer for Avengers 4, which revealed that the installment will be titled Endgame. And it certainly looks like we're building to something major. First, Tony Stark (Robert Downey Jr.) is hopelessly floating through space; later, Natasha (Scarlett Johansson) and Steve Rogers (Chris Evans) embark on make-or-break mission. In the course of the action Steve seems to be turning to his memories of Peggy Carter for solace. But is there a chance that Peggy will return in Avengers: Endgame? Steve's true love, who passed away in Captain America: Civil War, could come back if Steve and Natasha are actually traveling back in time.
The first clue that Avengers 4 would involve time travel arose in the Infinity War post-credits scene, which showed Nick Fury (Samuel L. Jackson) using a pager from the '90s to contact Captain Marvel (Brie Larson). It would make sense that the Avengers who'd survived Thanos's universe-shifting snap, which wiped out 50 percent of earth's population, would need to go back in time to collect each of the Infinity Stones before Thanos could get to them. Exactly how the Avengers could do that is still unknown, but it could likely involve Ant-Man (Paul Rudd), who'd accessed the Quantum Realm in Ant-Man and the Wasp.
Should the Avengers travel back in time to reverse the turn of events that played out in Infinity War, it seems likely that Steve Rogers would want to reunite with Peggy, (Hayley Atwell), who'd known him before he first "died" in Captain America: The First Avenger.
In order for Steve to reunite with Peggy in Endgame, he would likely have to travel back in time to the 1940s, which was the time when the co-founder of S.H.I.E.L.D. and Captain America first fell in love. Then again, Peggy returned in Captain America: The Winter Soldier, that time appearing as a 96-year-old woman. While it seems more likely that Avengers 4 will show a long-awaited reunion between Steve and Peggy when they were together, there is a theory that much of Endgame will take place during the Winter Soldier era. The main support for that theory comes from rumors, as shared by Digital Spay, that past villains like Crossbones (Frank Grillo) will make a comeback in the next Avengers movie, which now come out on April 26, 2019.
A less exciting and more logical explanation for why Steve's story might take him back to the past — for good — in Avengers 4 is the fact that Evans' contract ends with his sixth movie. That suggests that Endgame could very well be just that for Captain America.
The way that Steve caresses his picture of Peggy in the new trailer for Endgame suggests that he could either be returning to see her back in the time period when they met, or maybe that embarking on a suicide mission in order to prevent Thanos from seeking out those universe-altering Infinity Stones later. Either way, it seems like Avengers 4 will require a lot of tissues.