In a strange country where he is being hunted at any time, Casey (Scott Adkins) was entrusted by his master to come to New York with a legendary mysterious weapon. The master was eventually killed. In order to avenge his master and to uncover the truth about the treasure, Casey began to seek the mastermind behind the scenes through the few clues he had. When he gradually saw the light and learned that the mastermind behind the scenes was an international underground assassination organization, and that the assassination organization's powerful killer was his fellow apprentice, Casey was shocked and unwilling to face everything in front of him. He firmly believed that his brother was being used by someone, and there must be a bigger conspiracy behind this organization...