Nancy Drew and the Hidden Staircase (1939)
Genres: Mystery
Cast: Bonita Granville, John Litel
Nancy Drew and the Hidden Staircase is a 1939 American mystery film directed by William Clemens and written by Kenneth Garnet. It is fourth and last in a series of films starring Bonita Granville as teenage amateur detective Nancy Drew, Frankie Thomas as her boyfriend, and John Litel as her father. It was loosely based on the novel of the same name by Mildred Wirt Benson. The film was released by Warner Bros. on September 9, 1939.