 The picture was directed by Joseph Pevney and was based on the short story "The Sire de Maletroit's Door" by Robert Louis Stevenson.Its alternative title was "Robert Louis Stevenson's The Strange Door".Sire Alain de Maletroit (Charles Laughton), plots revenge on his younger brother Edmond (Paul Cavanagh) for stealing Alain's childhood sweetheart, who died giving birth to Edmond's daughter Blanche (Sally Forrest).