Harry Langford helps Five-0 investigate a series of murders that follow the plot of a fabled unpublished crime novel from the 1920s. Also, Tani and Junior's friendship takes a meaningful new turn.

Cast: Alex O'Loughlin, Scott Caan, Ian Anthony Dale, Meaghan Rath, Jorge Garcia, Beulah Koale, Chi McBride, Katrina Law, Taylor Wily, Dennis Chun, Kimee Balmilero, Anyssa, Fernando Chien, Perry Kainoa, John Harlan Kim