Why Steve Rogers HAD to Return: An "Avengers: Doomsday" Theory

Marvel has finally released the long-awaited Avengers: Doomsday teaser which confirms that Steve Rogers will, in fact, return for the upcoming film. Now, we're all left with a whole lot of emotions and thoughts and almost a full year to simply sit with them. Of course, this also means we have a whole lot of time to theorize about what this return means for the MCU. And isn't that what we Marvel fans do best?

A lot of Marvel fans were probably shocked by this teaser and the fact that Steve will be returning. I'll admit, I was caught off guard. However, the more I think about it, the more I realize, his return might just be necessary for Doomsday to happen. Here's my theory...

You, of course, remember that the last time we saw Steve Rogers in the MCU is when he went on a solo time travel adventure to return the Infinity Stones at the end of Avengers: Endgame. Instead of returning after a brief mission like he was supposed to, Steve lived a full life with Peggy Carter in a different timeline, before returning, now much older, to give Sam the iconic shield. Sam reluctantly accepted and asked Steve if he wanted to explain the wedding ring on his finger, to which Steve delivered the now heavily memed "no, I don't think I will" line. More on that later.

But what do we know about the MCU's rules of time travel? Steve didn't simply travel back to his own past to live out his life wit Peggy. Instead, when he decided to finally get that life Tony was telling him to get, he inadvertently created a branch timeline, one that was never supposed to exist. And with the TVA no longer pruning that sort of thing, the creation of this new timeline may have led to an incursion that triggered the death of another universe.

And that's where Doom comes in. What if Doom's universe was destroyed by the incursion caused by Steve's new timeline? A vindictive character like Doom is sure to seek revenge for that sort of thing. And while we have no way of knowing exactly what Doom will be capable of when we first meet him in the MCU, we can probably assume he'll have some multiversal capabilities at some point. So, Doom escapes the death of his universe and kills Steve Rogers for causing it. Yes, sorry everyone. Steve might be returning just to die. It's like Tony told him, "when you mess with time, it tends to mess back."

However, Doom won't truly accomplish his goal by killing Steve. Instead, he'll learn that, by killing him, all he is really doing is creating another branch timeline. Eventually, he'll realize that no matter what he does, he can only cause the multiverse to expand further. And so, his mission to destroy Steve Rogers will become his mission to destroy the multiverse and replace it with a single universe made in his vision. Hence, his apparent interest in Franklin Richards and his universe-creating abilities in the post-credits scene of The Fantastic Four: First Steps.

So the moral of the story is, Steve Rogers' one self-serving decision in his entire life, literally leads to the death of the multiverse.

But wait, there's more! It seems unlikely that Chris Evans returns as Steve Rogers just to be taken out of the picture (literally) in an opening scene. It would also make sense that Doom's ego wouldn't allow him to create his new universe without including Steve Rogers. He would want to make him suffer. So, Steve is likely going to have a role to play in this new universe and the events of Avengers: Secret Wars.

This means that he would be teaming up with the rest of the Avengers and New Avengers and Fantastic Four and... well, everyone else. But of course, that group of heroes would include Captain America himself, Sam Wilson. So this would mean, a Steve who has not yet given Sam the shield, would be fighting side by side with the new Captain America. Now, thinking about this too much will probably give you a headache so I would avoid that, but it also leads me to believe that Sam is going to have a key role to play in Secret Wars and Steve is going to see that. This will, in turn, inspire him to eventually go back and give Sam the shield, in that aforementioned Endgame scene. So when Sam asks him if he wants to share details about his life, a Steve who has survived the events of Avengers: Doomsday and Avengers: Secret Wars will reply with: "no, I don't think I will."

Avengers: Doomsday will hit theaters on December 18, 2026.