On Halloween, the team hunts a serial killer who mimics murders from a cult slasher film; Jerry is abducted by counterfeiters.
McGarrett meets a woman who helps him reopen the last cold case his father investigated before dying.
An old-school private detective helps the Five-0 solve the murder of a young woman who secretly worked as an escort.
When Chin and Danny are taken into custody over past deadly transgressions, McGarrett turns to Joe for help.