Marvel’s “Iron Man 3” pits brash-but-brilliant industrialist Tony Stark/Iron Man against an enemy whose reach knows no bounds. When Stark finds his personal world destroyed at his enemy’s hands, he embarks on a harrowing quest to find those responsible. This journey, at every turn, will test his mettle. With his back against the wall, Stark is left to survive by his own devices, relying on his ingenuity and instincts to protect those closest to him.