On November 2017, an anonymous 4chan user accurately leaked major plot points of Avengers Infinity War including the return of the Red Skull and Thanos sacrificing Gamora for the Soul Stone.
That same user wrote : “Iron Man reassembles the Avengers and decides to build his own Infinity Gauntlet to undo everything that Thanos did.”
“They recruit Ant-Man to help them travel through time and space using the Quantum Real to retrieve the Infinity Stones from different time periods. Thanos finds out about their plans and becomes hellbent on stopping them.”
“The movie revolves around the relationship between Captain America and Iron Man.”
The leak continues: “At one point, Captain America and Thor fight Thanos. Timeline alterations have restored Mjolnir, and Cap wields it against Thanos to allow the others to escape, and is killed holding Thanos off.
“At one point, Hawkeye must protect the unfinished Stark Gauntlet from Thanos' minions. He plays an ‘instrumental’ role in Thanos' defeat. Thor's subplot centres on him assembling an army to challenge Thanos. Captain Marvel joins him.”
The source added: “Hulk's subplot centres on Banner and Hulk finally merging to become Professor Hulk. He is the one that ultimately wields the Stark Gauntlet against Thanos, losing his arm in the process.”
“Nebula's subplot centres on her efforts to redeem herself. At one point, she fights her murderous past self. Several MCU movies are revisited and retconned (probably not permanently), such as the Avengers retrieving the Power Stone creating a timeline where the Guardians of the Galaxy never came together. There's a pivotal scene between Doctor Strange and a fully CGI character being shot on a secret location, with a skeleton crew, and which takes up a sizeable portion of the budget.”
They concluded: “Only two of the original Avengers (Cap, Stark, Thor, Hulk, Hawkeye and Black Widow) meant to survive the movie. Cap dies.
