Scott's (Chuck Norris) life is plagued by memories of his accidentally injuring a friend during the rigorous training he endured under a martial arts master. A wealthy heiress, who seeks revenge against an international terrorist training camp known as The Octagon, enlists his help through suspense and intrigue, because he is the only one who can defeat his adopted brother running the operation.

As Scott becomes perilously drawn to The Octagon he realizes his brother has turned to the dark side while training many different terrorist groups in the ninja style of killing using electrifying techniques and secrets only the two of them share.