AceShowbiz - There have been reports that some of the original Avengers will not return after "Avengers: Endgame", but this new theory shared by a Marvel fan just reveals a possible saddest scenario. This Reddit user shares his/her theory about how to resurrect the fallen heroes without undoing the snap.

The internet user who goes by the name Enervata thinks that Thanos didn't decimate half of the population. Instead, the Mad Titan may have created an alternate universe where all the "dead" now reside.

"Everyone is obsessed with 'undoing' the snap. What if they don't?" the fan wrote. "What if instead Thanos didn't actually wipe out half the universe's inhabitants with the snap, but instead created an alternate universe and tossed half the occupants into this other universe via the 'dusting.' "

The theory suggests that the "dead" superheroes now live in the alternate universe which Marvel will move forward with in the future. On the other hand, those who live at the end of "Avengers: Infinity War" are actually the ones who get left behind.

"Everyone who got 'dusted' is strongly implied to still be alive moving forward in the Marvel franchise (Spider-Man, Nick Fury, Dr. Strange, Black Panther, Wasp, Most of the Guardians, Bucky, etc.)," the fan explained the theory. "Everyone who is still alive at the end of Infinity War, have very uncertain futures in the movies moving forward (Cap, Thor, Iron Man, Hulk, Nebula, etc.) ... All the new guys got snapped, all the veterans were left behind."

Enervata further shared a reason why this scenario is very plausible, "If the snap gets undone, we still have headlining superheroes (Cap, Iron Man, Hulk, Thor, etc.) all waiting to launch into action to save the day again. That's a problem based on the future planned movie schedule. That means you'd have to kill off or explain why every major surviving character becomes retired after End Game's credits roll. That's difficult to achieve. Almost impossible to achieve even with 3 hours."

This theory, however, leaves lingering questions about how Gamora would be saved and what would happen to Rocket, who is still in the world with the old Avengers. Gamora was sacrificed by Thanos in "Infinity War", but she and Rocket are expected to return in "Guardians of the Galaxy Vol. 3".

"Avengers: Endgame" runtime is still 3 hours during recent test screenings. Directors Anthony and Joe Russo claimed that people's reactions were great after watching the movie, which has been dubbed the final installment of Marvel phase 3. It will bow in U.S. theaters on April 26.