Nancy Drew and the Hidden Staircase is a 1939 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.Synopsis
The elderly Turnbull sisters want to donate their mansion for a children's hospital. However, their father's will states that at least one of them has to stay in the house every night for twenty years before they can inherit the estate; there are two weeks left to go.
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