The Avengers
The Asgardian Loki encounters the Other, the representative of an extraterrestrial race known as the Chitauri. In exchange for obtaining the Tesseract,[c] a powerful energy source of unknown potential, the Other promises to provide Loki with an army to conquer Earth. Nick Fury, director of the covert agency S.H.I.E.L.D., arrives at a remote research facility where physicist Dr. Erik Selvig is leading a team studying the Tesseract. It suddenly activates and opens a portal, allowing Loki to reach Earth. Loki steals the Tesseract and uses his scepter to enslave Selvig and other agents, including Clint Barton, to aid him.
In response, Fury reactivates the "Avengers Initiative". Agent Natasha Romanoff travels to Kolkata to recruit Dr. Bruce Banner so he can trace the Tesseract through its gamma radiation emissions. Fury approaches Steve Rogers to discuss his knowledge of the Tesseract, and Agent Phil Coulson visits Tony Stark so he can check Selvig's research. Loki is in Stuttgart, where Barton steals iridium needed to stabilize the Tesseract. This leads to a confrontation with Rogers, Stark, and Romanoff that ends with Loki's surrender. While Loki is being escorted to S.H.I.E.L.D., his adoptive brother Thor arrives and frees him, hoping to convince him to abandon his plan and return to Asgard. Stark and Rogers intervene, and Loki is imprisoned in S.H.I.E.L.D.'s flying base, the Helicarrier.
The Avengers disagree on how to approach Loki and become argumentative once they realize S.H.I.E.L.D. plans to use the Tesseract to create weapons of mass destruction to use against extraterrestrial threats. During the argument, Loki's agents attack the Helicarrier, and in the chaos Banner transforms into the Hulk. Stark and Rogers restart the damaged engine while Thor attempts to stop the Hulk's rampage. Romanoff subdues Barton, freeing him from Loki's influence. Loki escapes after mortally wounding Coulson. Fury uses Coulson's subsequent death to motivate the Avengers to work together as a team. Loki uses the Tesseract and a generator Selvig built to open a portal above Stark Tower in New York City to bring his Chitauri fleet and start his invasion.
Rogers, Stark, Romanoff, Barton, Thor, and the Hulk work together to protect New York from the Chitauri. The Hulk incapacitates Loki while Romanoff learns from Selvig, now freed from Loki's mind control, that Loki's scepter can shut down the generator. Fury's superiors from the World Security Council attempt to end the invasion by launching a nuclear missile at Midtown Manhattan. Stark intercepts the missile and flies it through the wormhole toward the Chitauri fleet. The missile destroys the Chitauri mothership and disables their forces on Earth. Stark becomes unconscious, and his suit loses power, leaving him freefalling towards Earth. The Avengers manage to catch and resuscitate him, while Romanoff uses Loki's scepter to close the wormhole. In the aftermath, Thor transports an imprisoned Loki and the Tesseract to Asgard, where Loki will face Asgardian justice.
