Anecdotes

Third of four versions of "The Spiral Staircase." The first was Deux mains, la nuit (1946), the second was The Spiral Staircase (1961), made for television, and the fourth was Le secret du manoir (2000), also for television.

First cinematic color version of the "The Spiral Staircase" filmed adaptations of Ethel Lina White's "Some Must Watch" novel. This version was made entirely in England, although it retains the American setting, and is updated from the very early 20th century to contemporary times.

The film's source novel "Some Must Watch" by Ethel Lina White was adapted as a radio production starring Helen Hayes prior to Deux mains, la nuit (1946), the classic original version.

The voice of Dr. Rawley was overdubbed for the most part by Ed Bishop.

Second and final [to date, March 2017] theatrical feature film version of this story.