Nick Fury talks to Natasha Romanoff about the Avengers Initiative as they approach Tony Stark in the story of Iron Man 2. Fury and Stark discuss Tony’s actions while Natasha injects him with lithium dioxide. However, instead of improving his condition, the injection causes Tony’s death. The Watcher explains that in one universe, Tony becomes a member of the Avengers, but in this one, he does not.
Coulson calls Fury to tell him that he found Mjolnir. Fury captures Romanoff because she is accused of killing Stark and gives her a capsule. She is taken away from Crossbones and the team. She escapes. In New Mexico, Hawkeye shows Fury Mjolnir and they talk about it. Someone approaches and starts fighting the S.H.I.E.L.D. operatives at the base. Thor comes to get Mjolnir, but Barton accidentally drops an arrow and kills Thor before he can lift the hammer. Coulson and Fury talk about the deaths. Barton is found dead in his cell.
Culver University is in Virginia. Betty Ross is approached by Romanoff. She gives Ross the needle she stuck Stark with. When they look at it under a microscope, they see that it is frayed, which means it may have shot something. Romanoff finds out that Barton is dead. Fury thinks that Barton and Stark could be part of the Avengers Initiative, and Romanoff realizes that Bruce Banner is in the building. She tells him they need to leave.
Coulson goes to SHIELD as Loki and an army from Asgard arrive through the Bifrost bridge. Fury talks to Romanoff on the phone while she fights General Ross and the U.S. Army. Bruce gets shot and starts to turn into the Hulk. The Hulk starts to get bigger and bigger until it explodes, which upsets Betty. Fury agrees to bring Loki, who killed Thor, to SHIELD.
Romanoff logs into S.H.I.E.L.D. records using Coulson’s information. While looking at the records of agents, she realizes she is in the same room as the assassin. She calls and tells Fury “It’s all about Hope.” Coulson tells her that Fury is the last name on the Avengers initiative. Fury goes to talk to Loki with the Destroyer.
San Francisco. Hope Van Dyne is dead and Hank Pym goes to Fury at his daughter’s grave. Hank Pym is the Yellow Jacket and the person who killed Stark, Thor, Barton, Banner, and Romanoff. Fury uses Asgardian technology to show Loki that Pym is the true killer of Thor. Loki captures Pym but decides to stay on Earth.
Loki comes to the United Nations and speaks to the world as if they are his loyal followers. Fury removes the frost from Rogers’ coffin as Captain Marvel arrives.