Since the New York incident, Tony Stark (Robert Downey Jr.) has been troubled by unprecedented anxiety. He has been madly involved in the research and development of the upgraded version of Iron Man, and has been working day and night for this, even ignoring the feelings of his girlfriend Pepper Potts (Gwyneth Paltrow). At the same time, the notorious terrorist leader Mandarin (Ben Kingsley) has created a series of bombings, and Tony's most loyal bodyguard at the time was seriously injured in the latest attack. Not long after, Tony, Pepper, and Maya (Rebecca Hall), a female botanist who had once had a relationship with him, were attacked by fierce artillery fire at home and almost died. All this seems to be related to the research of the scientist Aldridge Killian (Guy Pearce) and his ultimate creature who met by chance 22 years ago. Even with sophisticated and advanced armor, it is impossible to dispel the anxiety from the bottom of my heart. How does Tony, whose everything is shattered, go through the blazing fire from hell...