The Falcon & the Winter Soldier episode 5 raises the possibility Steve Rogers returned to an alternate timeline after Avengers: Endgame. The final scenes of Avengers: Endgame essentially ended Steve Rogers' time as Captain America in the MCU, with Steve handing over his shield to Sam Wilson and choosing the Falcon as his successor. Rogers' fate was a mystery, made all the more mysterious because of Marvel's confusing and contradictory models of time travel, and fans naturally wondered whether he would return.

Falcon & Winter Soldier episode 5 felt like a response to that question, with a powerful scene in which Sam and Bucky discussed the fact their friend was "gone." They didn't define what they meant by the term, but it was clear they didn't envision dropping in for a chat and some advice from the elderly Steve Rogers, or having him pay them a visit either. They both seemed pretty confident they had said their final goodbyes on that fateful day when Steve gave up his shield, and Steve's continued absence has clearly left something of a hole in their lives.

Related: Marvel Retconned Avengers: Endgame's Biggest Captain America/Bucky Problem

But what has happened to Steve Rogers? Why is the goodbye so final? There are two possibilities - and it all depends on the model of time travel.

Avengers: Endgame Didn't Commit To Steve Rogers' Fate

The Ancient One explains the balance of time to Bruce Banner

Time travel is a theoretical science, and precious few franchises handle it consistently; films are stories first and foremost, not theses in quantum mechanics, so even when the "rules" are carefully established they tend to bend to the needs of the plot. Avengers: Endgame established that the past could not be changed, but then in one key scene the Ancient One explained branching timelines would be created by the removal of the Infinity Stones. "The Infinity Stones create what you experience as the flow of time," she explained to the Hulk. "Remove one stone and that flow splits." According to the Ancient One, these branched timelines are created because of the unique properties of the Infinity Stones and their relationship with the nature of reality. But that naturally raised a curious question; what exactly happened to Steve Rogers when he traveled back in time to live out his "Happily Ever After" with his beloved Peggy Carter? Had he been living in the background of the MCU all along, or had he lived in an alternate timeline?

Amusingly, the writers and directors of Avengers: Endgame can't agree on that. Scriptwriters Christopher Markus and Stephen McFeely point out that "the Ancient One specifically states that when you take an Infinity Stone out of a timeline it creates a new timeline. So Steve going back and just being there would not create a new timeline." In their view, there was a period from about 1948 to the present day in which there were two versions of Steve Rogers, albeit one was in a form of cryogenic suspension for some time. But the Russo brothers disagree, insisting Steve's time travel did indeed create a branched reality. Captain America traveled back to the main timeline in order to hand the shield over to Sam. As Joe Russo recently put it, "In our internal logic that we defined in the room, that was the choice that we made. Based on everything that happened, he would have been in a branch reality and then had to have shifted over to this, so jumped from one to the other and handed the shield off."

This disagreement may sound rather technical, but it's actually absolutely vital when it comes to understanding the fate of Steve Rogers. If Steve is now "gone" as far as the mainstream MCU is concerned, then what does that mean? Assuming Markus and McFeely are correct about Endgame's time travel rules, it can only mean Steve quietly passed away sometime after he passed on the shield. But if he traveled from another timeline, then there's another possibility - that he's gone back to his own branched reality, and Sam and Bucky don't ever expect to see him again.

Related: Why The MCU Calls Loki A 'Variant' After Endgame

The Loki Trailer Confirms The Ancient One Wasn't Being Entirely Honest

Loki Timelines Trailer Endgame

Avengers: Endgame may have been ambiguous in explaining its model of time travel, and just how easy it is to create a branched reality, but fortunately the MCU is continuing to develop the theme. The Loki trailer seems to strongly suggest the timeline is much more malleable than the Ancient One indicated to the Hulk, because there's an entire organization called the Temporal Variance Authority who protect the integrity of the timeline. In Avengers: Endgame, the time traveling heroes unwittingly created a single branched timeline they could not close off in which Loki escaped with the Tesseract. But the Loki trailer suggests at least thirteen branched timelines were created. The Ancient One was presumably oversimplifying for the sake of the Hulk, telling him what she felt he needed to know in order to be aware the Infinity Stones must be returned.

All this means it is far more likely Steve Rogers traveling back in time really did create a whole new branched timeline, one in which there were two Captains America. In truth, this model makes more sense in character terms, because it's hard to imagine Steve living a married life in which he ignored the shadowy manipulations of Hydra and his friend Bucky being brainwashed and transformed into the Winter Soldier; that just doesn't feel like something Rogers would do, even if he had decided not to serve as Captain America. Whatever changes he made to the timeline presumably affected the ultimate outcome of Avengers: Infinity War and Avengers: Endgame in the end, because notice he traveled to Sam and Bucky with a shield that was still whole, never having been broken by Thanos. The explanation favored by the Russo brothers fits what's seen on the screen a lot more, and works all the better thanks to Loki's development of the MCU's time travel mechanics.

Steve Rogers Could Have Returned To His Branched Timeline

Old Steve Rogers looking up in Avengers Endgame

Circling back to Falcon & Winter Soldier episode 5, this model of time travel means the elderly Steve Rogers hasn't necessarily passed away. When Sam and Bucky say Steve is "gone," they could simply be referring to his having returned to the branched reality he has lived in since 1948. That would make sense, because this is a timeline where Steve and Peggy have lived a happy life for decades. Even assuming Peggy has passed away in 2016, as in the prime timeline, Steve will have countless friends and even family there, perhaps children and even grandchildren.

If this theory is correct, then the MCU has indeed said its final farewell to Steve Rogers in Avengers: Endgame; the first Captain America might as well have died, explaining why the Avengers let the world think he perished battling Thanos, because he really is "gone." But the finality of this is not something to grieve, but rather something to rejoice, because Steve has now lived a happy and wholesome life in a timeline that may well have avoided some of the great tragedies of the MCU. He has gone home, to what is most likely a better world.

More: Falcon & Winter Soldier Is Telling The Post-Blip Story Endgame Couldn't

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