Noble-born cad Denis (Stapley) has been tricked into a forced stay at the eerie manor of the Sire de Maletroit (Laughton), an evil madman who can't get over the death of his beloved, 20 years after she married his brother (Cavanagh) instead, then passed away during childbirth. Maletroit is determined to have his revenge: the brother has been stowed away in the dungeon for two decades, while he's convinced his disreputable house guest will make a suitably hellish husband for his niece. As luck would have it, the young couple manage to fall in love, and with the help of manservant Voltan (Karloff), they try to make their escape, but not before a final confrontation with Maletroit in the dungeon's crushing deathtrap.—Stephen Cooke <[email protected]>

The wicked Alain, Sire de Maletroit (Laughton), plots elaborate revenge against his younger brother Edmund (Cavanagh). Twenty years previously, Alain's lover left him for Edmund and they ran away to marry; she died in childbirth. Alain imprisoned Edmund in the dungeon of the family manor, and convinced his young niece Blanche that her father was dead. When Blanche reaches adulthood, Alain plans to make her life miserable by marrying her off to a well-born cad, Denis de Beaulieu (Wyler). But Denis and Blanche fall in love and try to escape, leading to a deadly confrontation with Alain in his dungeon deathtrap.—balkaster