"Detective Sergeant Mariko Oshiro has been promoted to Japan's elite Narcotics unit-and with this promotion comes a new partner, a new case, and new danger. The underboss of a powerful yakuza crime syndicate has put a price on her head, and he'll lift the bounty only if she retrieves an ancient iron demon mask that was stolen from him in a daring raid. However, Mariko has no idea of the tumultuous past carried within the mask-or of its deadly link...