The Iron Giant is a colossal defensive machine originating from an unknown civilization from outer space. He cannot recall his purpose as the crash has apparently damaged his memory . He befriends a young boy who acts as a guide to this new world and provides the giant an unlimited supply of metal, which is apparently necessary for his functioning. A government agent however is seeking to find evidence of the mysterious robot so that the US military can destroy it before it does . Will the Iron Giant be able to suppress his true nature in the face of an imminent threat or will he bring chaos to the world?