How Loki Fixes Avengers Endgame’s Biggest Plot Hole

The Plot Hole

All of this brings us to the plot hole itself, as there have been two major theories as to how Cap arrived on that bench.

1. Multi-Verse Theory. Cap travelled back to the 1940s, returned the last Infinity Stone back to where it belongs, and began living a life with Peggy. Because he's altering Peggy's past, this fractures time and creates a separate reality where the pair live out their lives out together, maybe saving Bucky in the process and preventing the deaths of Howard and Maria Stark.

Anything goes - it's a full-on "What if?" that we never see.

Cap being on the bench comes from him using a remaining phial of Pym Particles (that he first took from the SHIELD base in 1970) to beam back at the exact time he knew he was supposed to return in the first place.

There's a whole wing of MCU fandom that think this HAS to be the way things go, because there's "no way" goodhearted Steve Rogers wouldn't interfere with the atrocities of our own history, whenever he could. Cap literally states in Civil War that he "wishes he could" leave some things be, but immediately takes that back, as he fundamentally enjoys doing the right thing.

2. One Timeline Theory. This revolves around Cap setting all the Stones back in place across the main MCU timeline (consisting of everything we've watched as an audience, that is referred to in Loki as the "Sacred Timeline"), settling into his life with Peggy in the background of all the other movies.

It means that between the 1940s and 2011, there are TWO Captain Americas on Earth - one in the ice, and another away from the spotlight, living his best life.

The problem is it clashes with an interpretation of the rules of Endgame - that you can't change the past - which I'll get back to. On the positive side, this theory lines up with the Agent Carter TV show, which always left Peggy's husband as a mystery, as it could've been Cap trying to hide his identity all along.