Wissenswertes

Whilst this film was based on Ethel Lina White's 1933 novel "Some Must Watch," there are several major differences. In the novel, the maid stalked by the killer was not mute. It was also set in contemporary England, not early 1900's New England. Finally, the title of the film and the idea of incorporating a spiral staircase as a thematic element comes from another source entirely: Mary Roberts Rinehart's 1908 novel "The Circular Staircase." The heroine of the book was not mute or crippled, nor were any of the murderer's victims.

The silent film seen being screened in the cinema at the beginning of this film is D.W. Griffith's The Sands of Dee (1912), from 1912, starring Mae Marsh and Robert Harron.

Rhonda Fleming erroneously and repeatedly claimed she had received a Best Supporting Actress Oscar nomination for her minor role as Blanche in this film. The movie did get an Academy Award nomination for Supporting Actress, but it was Ethel Barrymore as the family matriarch who was cited, not Fleming.

A good many plot elements in this film were picked up and used in An Unlocked Window (1965) of Alfred Hitchcock zeigt (1962). In that hour-long story, after an opening murder scene, pretty much the entire story unfolds in one evening, a dark and stormy night, and takes place in an old Gothic style house. Also, there is a seriously ill patient under a nurse's care upstairs and who only occasionally wakens, a drunken cook in the kitchen, a handyman who must go out in the night on an errand, and a murderer right under the roof all evening and not revealed till the closing moments.

Joan Crawford, after receiving critical praise for her performance in Erpressung (1941), at one point campaigned for the role of the mute later girl played by Dorothy McGuire. Crawford also owned the rights, but MGM studio chief Louis B. Mayer vehemently opposed the idea, telling her "No more cripples or maimed women".

Robert Siodmak: the close-ups of the killer's eyes and hands.