This post may or may not contain possible spoilers for the upcoming Avengers Endgame film. Proceeded at your own risk.
Last week an extremely detailed post on Reddit had massive spoilers for Endgame.Most of the claims could be simply guesses at best, but there’s something about this particular comment that has people wondering if it’s the real deal. Perhaps it’s one or two similar descriptions it shares with another potentially big leak from a different source that hit the web around the same time, so it’s unlikely that the two authors saw each other’s work. In any case here are the detailed spoliers
Tony/Nebula make it back to earth
Marvel there, entire team heads to Thanos
He’s weakened, the team, especially b/c of Marvel, kill him. Gauntlet is broken and stones can’t undo the snap
They couldn’t protect the universe, so they avenged it.
Thanos meets Death (the girl everyone thinks was cast as Ant-Man’s daughter). He’s pleased with himself
A few years later, Ant-Man returns, explains Quantum stuff
Tony builds out Quantum suits, teams split off to recharge stones at various points in time
Rest of act is interaction between present/past selves/teams, powering stones
Thanos has been watching the entire time, now concerned they could undo his plan, begs Death to let him preserve his work
Thanos + outriders attack Avenger HQ to prevent new gauntlet from being used
Cap/Tony/Hulk ‘quantum’ away to Wakanda battle using new gauntlet, only to miss and end up on Xandar after Thanos battle there
Gauntlet isn’t strong enough to beat Thanos, big fight between those three until it’s Cap vs. Thanos
Cap is able to use the gauntlet one last time “Avengers Assemble” bringing EVERYONE to face him – that’s the huge fight scene
In real-time Thanos at Wakanda sees the stones weakening from his gauntlet because in this timeline he’s defeated
Thanos is killed at Wakanda (Cap sacrifices himself) and now the snap never happened so the events of the movie basically never happened
Dr Strange does some hand-wavey saying the loop is now closed for the 14 millionth time, and we won.
Again, none of this is confirmed at all. It could simply be some fan fiction but who knows
Credit BGR.com for these spoilers