Loki's Invasion

At first, when it seemed to be no progress with it, the Avengers Initiative was shut down. Gideon Malick put the focus on Phase 2, an initiative to reverse-engineer HYDRA weapons to create weapons for Earth's defense and examining the Tesseract as a source for such weapons. Loki arrived through the Tesseract from "the other end of space" and began attacking several S.H.I.E.L.D. agents, taking control of Hawkeye and Erik Selvig with the Scepter and taking hold of the Tesseract. Following this, Nick Fury reinstates the Avengers Initiative and has Phil Coulson call for Black Widow to bringing in the others. Coulson has her go to Kolkata, India to bring in Bruce Banner, who can track the cube due to the fact that it is emitting low levels of Gamma Radiation, of which Banner is an expert. Meanwhile, Fury goes to Captain America to give him his first mission since being awakened. Coulson personally travels to Stark Tower to bring Tony Stark files containing information regarding his other potential teammates, Loki, and the Tesseract

Tony Stark's first choice was his old friend Hank Pym and his wife Janet Van Dyne, Hank was against helping due to a past dispute with Tony but Janet convinced Hank to which would ultimately be her undoing.

After that, Tony tracked down Namor to a boat in the Atlantic, the Invader agreed after some easy convincing but did not come with Tony taking his own route (the sea).

The team was assembled on the Helicarrier and initially had difficulty working together. Many of them did not want to form a team and they argued constantly over ideological differences. Tony Stark was reluctant to work under the command of Captain America. Thor demanded that Loki be returned to him and did not want to compromise. Everyone on the team was uncomfortable with the presence of Bruce Banner. After Loki killed Phil Coulson, and began his main attack, the Avengers decided to put their differences aside and went to New York City. During the battle they learned to trust one another and rally in defense of New York as it was invaded by extraterrestrials known as the Chitauri. Captain America took command of the team and they all worked to suppress the invasion force. A Large Chitauri beast flew towards Midtown High, Hank and Janet went inside it hoping to kill it. But after finding the only way to get to the heart was to go Subatomic, Janet sacrificed her life doing so saving the school. Hulk beat Loki into submission and Iron Man carried a nuclear weapon fired by the World Security Council into the portal through which the aliens entered Earth and destroyed their fleet, breaking the neural connection with their ground troops and instantly incapacitating them. Afterwards the team went to relax and have dinner together while Thor took Loki back to Asgard