"Iron Man 3" follows the title character as he attempts to stop a new villain called The Mandarin from taking over the world. Iron Man must also confront issues in his personal life, such as his post traumatic stress disorder.
"Iron Man 3" is the first movie in the Marvel Cinematic Universe set after the events of "The Avengers," in which Tony Stark, played by Robert Downey Jr., helped save the world as Iron Man by disposing of a nuclear weapon during a battle in New York City. The stress of the battle has taken a toll on Stark, giving him nightmares and straining his relationship with Pepper Potts, played by Gwyneth Paltrow. Potts believes that the only way to overcome the trauma is for Stark to retire as Iron Man.
In addition to personal turmoil, Stark must contend with the Mandarin, a mysterious terrorist attacking the United States. Stark soon discovers that the Mandarin is nothing more than an actor hired by Aldrich Killian, a formal rival of Stark. Killian is developing a dangerous new technology called Extremis, which frequently malfunctions, killing its users. However, Killian and some of his associates were granted superpowers as a result of Extremis, and Killian is determined to use his powers to kill Stark, as revenge for a personal slight. The film ends with Stark, as Iron Man, defeating Killian in battle and promising to retire to save his relationship with Potts.