Friday the 13th part 8

The Spiral Staircase (1946) Directed door Robert Siodmak, is a psychological film noir starring Dorothy McGuire as the primary character, Helen.
It was adapted from a screenplay door Mel Dinelli and based on the Ethel Lina White novel 'Some Must Watch'. White also penned the original story that was used for Hitchcock’s film, The Lady Vanishes.
The movie is set primarily in a large Victorian house, Helen is a mute servant girl for the elderly bed-ridden Mrs. Warren (Ethel Barrymore). Also living in the mansion are the matriarch’s son Steve (Gordon Olivier), her stepson, Professor Albert Warren...