Nancy Drew and the Hidden Staircase (film)

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.

Then some strange things start occurring. A stranger forces his way past Nancy Drew Bonita Granville and brazenly searches the Drew house for related affidavits her lawyer father Carson John Litel has obtained. Then, the Turnbulls chauffeur Phillips Don Rowan dies, though it is uncertain if it was a murder or a suicide. The frightened old ladies consider leaving their home. When Nancy recognizes the dead man as the trespasser, she begins investigating, dragging her boyfriend Ted Nickerson Frankie Thomas into one predicament after another, eventually getting him fired and jailed.When police Captain Tweedy Frank Orth arrests the two sisters for Phillips murder, their ownership is endangered. Just in time, Nancy and Ted discover a secret passageway in the basement linking it to the neighboring house, owned by Daniel Talbert William Gould. Talbert would make a lot of money if a racetrack were to be built on the two properties, but the Turnbulls had turned down an offer to buy their place. ........

Source: Wikipedia