Avengers: Endgame is back in theaters and the Russo Brothers are out promoting it. While the directors weren't able to discuss too much during the first promotional tour, they are able to talk about everything now. One of the questions that keeps coming up involves what happened when Captain America went back in time to return the Infinity Stones. We finally have an answer to that question now, thanks to the Russos.

At the conclusion of Endgame, Captain America decides to go back in time to return the Infinity Stones. However, he also decides to go back further and live the rest of his life with the love of his life, Peggy Carter. Cap then returns as an elderly man to hand off his shield to Falcon. When asked about the specifics of the situation, Anthony Russo had this to say.

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"The way that it would work is that when Captain America goes back, he would create a branch reality. Now he would exist in that branch reality with a second Captain America who was frozen in ice."

As for how far back Captain America went back, that is another question. There are now technically two versions of Steve Rogers in the Marvel Cinematic Universe timeline by Anthony Russo's explanation. Joe Russo says, "Peggy understood that he was dead at that point in the storytelling" and this is because "Cap went back to a point in time where nobody knew he still was alive, frozen in ice." This all seems pretty convenient, though some hardcore MCU fans will still disagree with the branch realities.

Ok, so now we know what Captain America did at the conclusion of Endgame, but how did he come back to the current timeline? Anthony Russo says, "if he created a branch reality, he would then have to use Pym Particles to come back to this reality to hand that shield off." While the explanations make sense, they may spell trouble for the future of the MCU and its timeline, which Endgame has gone back and tweaked quite a bit. With that being said, Marvel Studios boss Kevin Feige will shed some more light on the situation this summer during San Diego Comic-Con and the D23 Expo.

Endgame has been rereleased into theaters with bonus content in an effort to become the highest grossing movie of all time. Marvel Studios is a little over $30 million away from taking down James Cameron's Avatar, so the battle for the throne will take a lot longer than expected. However, there are many who believe Endgame won't be able to accomplish the lofty goal at all. In the end, we'll just have to wait and see. While we wait to find out, you can check out the full interview with the Russo Brothers below, thanks to the Fox 5 DC YouTube channel. The Captain America portion is at about the 6-minute mark.