“Life hangs by a slender thread.”

Twenty years ago Sir Alain de Maletroit (Charles Laughton) imprisoned his brother Edmund (Paul Cavanagh) in an act of revenge. He was in love with a woman who his younger brother stole from him. She then died giving birth to his niece Blanche (Sally Forrest). Believing that both her parents are dead Blanche lives with her uncle as her guardian. Alain’s revenge is not only foisted upon Edmund. He also quietly takes revenge against Blanche by ensuring that anyone or anything that makes her happy is mysteriously removed.

Now that Blanche is twenty Alain intends to further ensure that she has a life of misery by marrying her off to the worst depraved person he can find. He tricks drunken womanizer Denis de Beaulieu (Richard Stapley) into believing he has murdered a man. When a mob chases him Denis escapes by entering the Maletroit chateau via a door that has no handle on the inside. Alain keeps Denis a captive and threatens him if he refuses to marry Blanche.

Wishing to torture Edmond some more Alain goes to the dungeon and tells him that he has arranged a marriage between Blanche and the depraved Denis. Edmond appears to be a man whose is mentally unbalanced from being in a dungeon for the last twenty years. When Alain leaves Edmond, now appearing sane asks the family servant Voltan (Boris Karloff) to kill Denis before the wedding. When Voltan goes to Denis’s room to kill him, Blanche shows up and begs her loyal servant to help Denis escape. In talking to Denis she has learned that he is not as wretched as her uncle thought. They are beginning to fall in love with each other. Denis decides to stay to try to help Blanche.

The marriage goes forward but Denis finds an old friend at the wedding who agrees to help them escape. The attempt fails. Alain captures them and seals Edmond, Blanche and Denis in a stone cell. The cell is powered by a waterwheel that presses the cell walls inward to crush them to death.

“The Strange Door” was released in 1951 and was directed by Joseph Pevney. The movie was based on a book by Robert Louis Stevenson. The movie takes place in 17th century France. It is considered a horror/thriller and a film-noir. It really isn’t a horror movie but more of a melodrama. Universal relied on Boris Karloff still having star power even though he is a supporting actor for the movie. He’s good but his part is very small. Charles Laughton is the principal star, and his performance was perfect. He is exquisitely oily and diabolical. A sadist built from insanity.

If you’re looking for a horror movie this is not it. If you’re looking for a Gothic romance with a little swashbuckle thrown in it’s a good choice.