The Unknown

In a grand Kentucky mansion, Captain Selby Martin and his tyrannical wife Phoebe host an engagement party for their timid daughter Rachel, whose marriage to James Wetherford has been arranged by Phoebe. While the guests mill around downstairs, Rachel lingers in the study with Richard Arnold. Martin finds them together, and Rachel reveals that they have been secretly married for several months. When Martin brandishes a gun and orders Richard to leave, he and Richard struggle for the gun and Martin is accidentally killed. Phoebe enters the study and sends Rachel to her bedroom, then orders Richard to leave, stating that she will not allow Rachel to live with the man who killed her father. Determined to avoid scandal, Phoebe orders her sons, Ralph and Edward, and Rachel to help her entomb Martin's body in the study fireplace, then forbids them ever to mention the occurrence. Months pass as Rachel becomes mentally unbalanced and gives birth to a baby girl, whom Phoebe immediately has sent away. Years later, the child, now a grown woman named Nina, returns to the home where she was born for the reading of Phoebe's will. Nina has never met any of her relatives, and as she was reared by a succession of teachers paid for by a mysterious benefactor, she is eager to have a family. Accompanied by private detectives Jack Packard and Doc Long, who have been hired by her benefactor, Nina is disappointed by her anti-social uncles, the embittered Ralph and deaf Edward, and the deranged Rachel, who cares for an imaginary baby and believes that Richard is returning any day. Also at the house are attorney Reed Cawthorne and Joshua, the family's longtime servant. That night, Rachel is awakened by the crying of a baby, and her search for the infant wakes Nina. Nina tends to her addled mother, while Ralph and Edward insist that the will be read immediately. When everyone assembles, however, Reed discovers that the will has been stolen. Ralph triumphantly announces that, without a will, the estate will pass to him, Edward and Rachel, and that Nina will receive nothing. Later that night, Nina is woken up by the sounds of a baby crying, and when Doc and Jack investigate the noise, they find a secret entrance inside the family crypt that leads to a tunnel going back to the house. Inside the tunnel is also a secret room, which contains evidence of recent use. While Jack and Doc are away from the house, a shadowy figure whispers to Nina and pushes her down a flight of stairs. Nina is not seriously injured, and when she regains consciousness, she frees Jack and Doc from the locked study, which is the endpoint of the tunnel. The next morning, a hysterical Rachel babbles about her father's accidental death, and Jack deduces that his body must be hidden in the walled-up fireplace. More mysterious occurrences that night lead to the discovery of Edward's body in the crypt, where he had been stabbed to death. While searching the grounds, Reed finds Richard Arnold, who was summoned by Nina's benefactor. Richard, who does not know of Nina's existence or Rachel's insanity, has come because the benefactor implied that Phoebe had included him in her will. Richard brushes aside Nina's attempts to befriend him, but softens upon seeing Rachel. Hoping to tie up all of the loose ends, Jack announces that he is going to tear open the fireplace. As he had hoped, the announcement draws out Phoebe, who confesses that she faked her death after learning that she had only a short time to live. Phoebe also reveals that she is Nina's benefactor, and that she hoped her "death" would bring Rachel, Richard and Nina together. Jack does not have long to confer with Phoebe, however, for shortly after their interview, she is killed and placed in her formerly empty coffin. While searching for the killer, Jack and Doc are locked in the secret room, and Rachel and Nina, lured by the crying sound, are surprised by Ralph in the crypt. Ralph reveals that he used a doll's crying mechanism to aggravate Rachel's condition, and confesses that he killed Edward and Phoebe because of his own insane hatred for his family. Joshua frees Jack and Doc, and they rush to rescue Nina and Rachel. Ralph is taken away by the police, and later, at the reading of Phoebe's will, Nina sits by her parents, who hold hands and look forward to the future.