Since the New York incident, Tony Stark (Robert Downey Jr.) Perverted by unprecedented anxiety disorders. He devoted himself to the development of an upgraded version of Iron Man, forgetting to sleep and eat, and even ignoring the feelings of his girlfriend Pepper Potts (Gwyneth Paltrow). At the same time, the notorious terrorist leader Mandalin (Ben Kingsley) carried out a series of bomb attacks, and Tony's most loyal bodyguard was seriously injured in the latest attack. Not long after, Tony, Pepper, and Maya (Rebecca Hall), the female botanist whom he had met once, were attacked by heavy artillery fire at their home and almost died. All of this seemed to be related to the scientist Aldridge Killian (Guy Pearce) and his ultimate creature he encountered by chance 22 years ago. Even with sophisticated and advanced armor to protect it, it cannot dispel the anxiety from the bottom of my heart. Tony, who has been shattered, how does he travel through the fierce flames of hell...