The Strange Door

In 17th century France, Sire Alain de Maletroit (Charles Laughton) plots an elaborate revenge against his younger brother Edmund (Michael Pate) after Edmund steals Alain's childhood sweetheart, leading to a deadly confrontation in his dungeon deathtrap. Alain imprisons Edmund for 20 years, convincing his daughter Blanche (Sally Forrest) that her father is dead, intending to force her into a marriage with the drunken cad Denis de Beaulieu. However, Denis shows unexpected redemptive qualities, and with the help of Voltan (Boris Karloff), Blanche and Denis fall in love, leading to a thrilling escape from Alain's clutches.