Detective Riko is a strong female cop, whose husband has been killed, leaving her with a small child. On a day off with her son, she meets a disturbed woman in a park who claims her child is in hospital. While investigating the murder of a woman in a hotel room, Riko finds that the park woman's husband is a suspect. The case seems to connect to un old, unsolved kidnapping case, but when Riko is herself kidnapped by a gangster, she gets the break that she needs.