Edward Stillwell, a kindly old music store owner, engages unscrupulous private detective Don Gale to locate Elora Lund, a young girl he has not seen in seven years. Although Stillwell refuses to explain why he wants to contact Elora, he tells Gale that finding her could make the detective a wealthy man. Three days later, a young woman enters Stillwell's shop and introduces herself as Elora. Unaware that Harry Pontos, a thief, is eavesdropping on their conversation, Stillwell informs Elora that he has some of her late mother's possessions which may be of great value. When Stillwell leaves the shop to phone Gale, Pontos sneaks into the cellar and takes a box labeled with Elora's name, thinking that it may contain the valued items. After Stillwell returns, Pontos steals up the stairs, kills the old man and kidnaps Elora. Soon after, Gale arrives and upon finding Stillwell's body, notifies reporters that Elora is an impostor. When Pontos reads the news story about the impostor, he releases his prisoner, whose name is Freda Hanson, a woman hired by Gale to pose as Elora and claim her inheritance. After Freda is freed, Gale visits her at her apartment, but is asked to leave by the building manager, James Summers. With Freda's help, Gale locates Pontos' hideout, but the police arrive just as he is searching the premises. Awakened by the sound of the police pounding at the door, Pontos grabs his gun and starts shooting while Gale slips out the window. After gunning down Pontos, the detectives chase Gale, who loses his shoe during the pursuit. Recognizing Gale, the detectives, Burns and Taggart, proceed to his apartment to interrogate him about Stillwell's murder. When Gale refuses to cooperate, they arrest him. Meanwhile, the real Elora, who was injured in an accident and is recuperating in a sanitarium, sees the newspaper account of Stillwell's murder and notifies the police. Believing that Gale is involved in the murder, Taggart and Burns decide to release him and send Elora to visit him at his office to find out what he knows. After being released from jail, Gale goes to Freda's apartment and accuses her of turning him in to the police so that she could claim the fortune for herself. Before Freda can reveal the nature of Elora's legacy, however, the doorbell rings and Gale hides in the bedroom. There he discovers a newspaper clipping about some rare Jenny Lind recordings and realizes that they must be Stillwell's treasure. When Gale walks back into the living room, Freda is no longer there, so he returns to his office, where he is greeted by Elora. Planning to cheat Elora, Gale holds her incommunicado in a house owned by Rose Denning, one of his operatives. After Summers discovers Freda's strangled body hidden in the closet, the police suspect Gale of the crime. Their suspicions are reinforced when the desk clerk remembers Gale visiting Freda on the night of the killing. Now charged with murder, Gale goes into hiding and decides that he must locate the recordings to exonerate himself. Sneaking into Stillwell's basement, Gale finds Summers there with an accomplice. After admitting that he learned about the recordings from Freda just before killing her, Summers finally discovers the prized wax cylinders. Gale then pulls his gun, and in the ensuing battle, shoots Summers and his accomplice and runs up the stairs. As Gale phones police headquarters to turn over the killers and the recordings, the police, alerted by the sound of gunfire, raid the cellar. Mistaking the police for Summers, Gale blindly fires into the cellar, and the detectives fire back, killing him and shattering the fragile cylinders.