Based on Carolyn Keene's novel, Nancy gets Ted to help her find a murderer trying to scare two old ladies out of their house.
Reporters ask Nancy Drew (Bonita Granville) why the Turnbull sisters are donating their house for a children's hospital. Her father Carson Drew (John Litel) says the will requires one sister to sleep in the house every night for twenty years; only two weeks remain. A man barges in and demands the affidavits from Nancy; but she signals iceman Ted Nickerson (Frankie Thomas), who chases him away. Nancy gets Ted to take her to Rosemary Turnbull (Vera Lewis) and Floretta Turnbull (Louise Carter), who say their chauffeur was shot. Captain Tweedy (Frank Orth) says it was suicide; but the D. A. disagrees. Nancy has Ted write a suicide note and plants it. They see that the victim Phillips was the man in the house. Nancy assures the sisters they are safe. With Ted's belt she measures the distance the shell was from the body and gets Ted to fire a similar gun, proving it was murder. Ted is arrested for shooting in a game reserve.
The Turnbull sisters tell Captain Tweedy they were robbed while the doors were locked. Nancy and her father say Phillips was murdered. The sisters heard voices and fear ghosts. Nancy learns race-track people want to buy their house. At night Nancy and Ted sneak in, and Nancy has Ted sleep in the basement with a camera, to which he attaches a string. Outside Nancy is grabbed by her father and taken home. While Ted sleeps, a thief trips the string. Nancy finds Ted arrested for wearing a dress. Nancy shows Tweedy a threatening note to stay away from the Turnbull house. Ted and Nancy develop the photo that reveals a secret door. They find Tweedy arresting the sisters for murder. Nancy and Ted break in, and Nancy calls her father to get the sisters out. After much effort Nancy and Ted find the secret door, and a passage leads to the house of Talbert (William Gould). Ted finds his clothes, and Nancy discovers race-track plans. They hide as Talbert comes in. Talbert finds them, and Ted fights him, knocking him out. Carson Drew argues with Tweedy, who sends Smitty (George Guhl) to the Turnbull house. Ted and Nancy are trapped, and Ted uses a hose. Smitty calls Tweedy for a plumber. Tweedy arrives and falls underground into the water. Talbert is arrested for murder, but Ted is arrested for writing the phony suicide note.
This amusing mystery moves quickly with persistent youthful
energy as the precocious Nancy manipulates Ted into committing
several crimes to help her solve the case and preserve the ladies'