Richard Arnold (Robert Wilcox) and Rachel Martin (Karen Morley) were secretly married. The couple plans on escaping the family ties on the night the Martins plan on announcing the arranged marriage of Rachel to family friend James Wetherford (Robert Kellard). When the couple tries to leave the Martin estate they are stopped by Rachel’s father, Captain Selby Martin (Boyd Davis). When the captain pulls a gun on Richard, they struggle for it, and it goes off. Rachel’s mother, Phoebe Martin (Helen Freeman) enters the room and orders her daughter to return to her bedroom. After she leaves the captain falls to the floor dead. Phoebe forces Richard to leave and does damage control. Years later Phoebe dies.
The remaining heirs to the Martin estate, Edward Martin (James Bell), Ralph Martin (Wilton Graff) and Rachel Martin Arnold are still living in the house. Before the will is read, Nina Arnold (Jeff Donnell) arrives at the mansion. She tells the family attorney, Reed Cawthorne (Mark Roberts) that she is the daughter of Rachel and Richard. She has with her two detectives, Jack Packard (Jim Bannon) and Doc Long (Barton Yarborough), which were hired to help her gather proof of her birthright and present it to the attorney.
According to Reed, claimants to the estate must remain in the house until the reading of the will. Jack, Doc and Nina settle in. Other than the butler, Joshua (J. Louis Johnson), the only other residents are Edward, Ralph and Rachel. All of whom have psychological issues due to the abuse of their overbearing mother. As soon as the newcomers are situated, strange things begin to happen.
“The Unknown” was released in 1946 and was directed by Henry Levin. It is an American crime mystery thriller with some old dark house elements. This is the third and final film that Columbia produced based on the “I Love a Mystery” radio series. The other films in the series were “I Love a Mystery” 1945 and “The Devil’s Mask” 1946. The radio series ran from 1939 to 1944 and was created by Carleton E. Morse. The film is a loose adaptation of the I Love a Mystery radio episode “Faith, Hope, and Charity, Sisters”.
The movie started out a little on the heavy side with lots of gothic overtones. A monologue is given by matriarch Phoebe Martin that brings the viewer up to date with the entire family trauma. It began to lighten up a little when Jack and Doc arrive on scene and started their investigation into the creepy goings on in the house. Soon you are knee deep in secret passages, crypts and weird characters. It then becomes your average 40’s style murder mystery. There are a few light moments but most of the film is played seriously.
There is some evidence that the children’s television show “Scooby Doo-Where Are You!”, by Hanna-Barbera, was created based on the “I Love a Mystery” radio series. Allegedly, Fred Silverman pictured the children’s show as a combination between the radio program, “The Archie Show” cartoon characters and “The Many Loves of Dobie Gillis” television program characters.