When John Mack, an aging government assassin, agrees to revitalize a highly classified government operation, he crosses paths with a sinister organization and is deceived into believing his killings are in the name of justice. Mack is pursued by a criminal syndicate which launches an operation to determine his identity and hunt him down. A romance develops with a female operative that changes Mack's outlook on the entire mission and calls into question his values. Unless he can turn her into a double agent, he faces the prospect of eliminating the first woman he has fallen in love with. With the first killings not in the name of justice, Mack has committed murder. With no easy way out, Mack struggles to continue the mission. Unable to go to the authorities, he must outwit his adversaries and find a way to end the mission and disappear. Convinced the syndicate will not let him leave the mission alive, the stage is now set for a shootout which leaves one man standing and another man dead.