AVENGERS!

S.H.I.E.L.D. Director Nick Fury (Samuel L Jackson) arrives at a remote S.H.I.E.L.D. facility during an evacuation. The Tesseract, an energy source of unknown potential, has activated and it opens a portal through space from which the exiled Norse god Loki (Tom Hiddleston) steps through. Loki takes the Tesseract and uses his abilities to take control of the minds of several S.H.I.E.L.D. personnel including Dr. Erik Selvig (Stellan Skarsgard) and Agent Clint Barton (Jeremy Renner) to aid him in his getaway. In response to the attack, Fury re-activates the Avengers Initiative. Agent Natasha Romanoff (Scarlett Johannson) is sent to India to find and recruit Dr. Bruce Banner (Mark Ruffalo) while Agent Phil Coulson (Clark Gregg) approaches Tony Stark (Robert Downey Jr.) and requests that he review Dr. Selvigs research. Fury himself approaches Steve Rogers (Chris Evans) with an assignment to retrieve the Tesseract from Loki. During his exile, Loki encountered the Chitauri, an alien race seeking to conquer the galaxy. In exchange for the Tesseract, the Chitauri agree to help Loki subjugate Earth. Suiting up, Captain America and Iron Man travel to Germany to apprehend Loki, who is recovering iridium needed to stabilise the Tesseract's power, and demanding that the civilians kneel before him. Loki quickly surrenders when the two heroes arrive, and he is escorted back to a S.H.I.E.L.D. Helicarrier, a high-tech, flying aircraft carrier. However, Thor (Chris Hemsworth), Loki's half-brother and the Norse God of thunder, arrives and attempts to free Loki so he can try to reason with him on his own, but he gets into a fight with Iron Man and Captain America. Eventually, Loki is taken to the Helicarrier and placed in a cell designed to hold the Hulk. The Avengers argue and deliberate over how to approach Loki and the revelation that S.H.I.E.L.D. plan to harness the Tesseracts power to develop weapons. Fury admits that the events in New Mexico a year before made S.H.I.E.L.D. aware of other races on other worlds, some of which may see Earth as an easy target. The decision was made to produce weapons with the Tesseract as a means of deterrence. As the group argue, Clint Barton and Lokis possessed agents attack the Helicarrier, disabling its engines in flight. As Stark and Rogers attempt to restart the damaged engines, Thor tries to prevent Dr. Banner from turning into the Hulk and destroying the ship from inside. While fighting Barton, Romanoff discovers that a blow to the head powerful enough to knock him unconscious is enough to break Lokis mind control. By the end of the battle, Loki escapes, Thor and Dr. Banner have been ejected from the ship and Agent Coulson is killed. Fury uses Coulsons death to motivate the Avengers into working as a team. Stark and Rogers realize that simply defeating them will not be enough for Loki. He needs to overpower them in a very public way so as to validate himself as ruler of Earth. Using a device built by Dr. Selvig, Loki opens a portal to the Chitauri home world over Manhattan, summoning a Chitauri invasion. The Avengers rally in defense of New York, but quickly come to the conclusion that they will be overwhelmed as wave after wave of Chitauri descend upon Earth. With help from the reformed Barton, Captain America and Thor evacuate civilians while Dr. Banner transforms into the Hulk and goes after Loki, beating him into submission. Romanoff makes her way to the portal, and she hits Dr. Selvig over the head, freeing him of Lokis control. Dr. Selvig reveals that Lokis staff can be used to close the portal. Meanwhile, the directors override Fury and send a jet that fires a nuclear missile at Manhattan to end the invasion. Iron Man intercepts the missile and directs it at the portal and the Chitauri home world before running out of oxygen and plummeting back to Earth, but the Hulk catches him as he falls. Thor escorts Loki and the Tesseract back to Asgard, while Fury notes that the Avengers will go their separate ways until such time as a new world-threatening menace emerges. In a post-credits scene, the Chitauri leader The Other tells his master that it is futile to attack Earth, as fighting The Avengers is like courting death. His master turns, revealing himself to be Thanos.