While Avengers: Endgame provided closure for some of the MCU's biggest characters, it also opened up doors to much bigger (and complicated) concepts, including a multiverse theory and time travel. The Avengers created several branch realities in their mission to secure the Infinity Stones of the past. Steve Rogers (Chris Evans) decided to stay in an alternate timeline so he could grow old with his true love, Peggy Carter (Hayley Atwell).

What we didn't know, however, was whether or not Captain America actually altered the past. Either he did, or rather he traveled back to the main timeline to reunite with Bucky (Sebastian Stan) and Sam (Anthony Mackie) as an old man. Finally, the Russo Brothers have explained the mystery once and for all.

During an interview with the podcast Lights Camera Barstool, Joe Russo gave some insight into his and his brother's thought process behind Steve Rogers' timeline. “One thing that’s clear that Anthony and I have discussed, I don’t know that we’ve discussed this publicly at all, Cap would have had to have traveled back to the main timeline," he explained. "That’s something that, yes, he would have been in a branch reality, but he would have to travel back to the main timeline to give that shield to Sam Wilson.”

Russo also confirmed that it was possible for Steve to exist in multiple realities. “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,” Russo stated. Mystery solved.

This information will prove useful as we head closer to the Disney+ series premiere of The Falcon and the Winter Soldier. The show will explore Sam Wilson's transition into the role of Captain America, and this important detail helps us understand how that will be possible.

Gallery — The Biggest Plot Holes In Marvel Movies:

More From Y105