Old Silas Blackburn, a wealthy recluse, lives alone with his ward Katherine and his butler. One night, Katherine discovers Silas murdered in the room where three generations of Blackburns have mysteriously died. Silas' grandson Robert, whom Katherine loves, comes to visit the next day, suffering from amnesia. When the detective sent to investigate is found murdered in the room the next morning, suspicion points to Robert, but Katherine believes him innocent. After Silas' burial, the household is amazed to return from the cemetery and find him sitting in front of the fire. Facts reveal that Silas had a twin brother whom he murdered when he demanded a portion of the family fortune. When his brother's daughter appears, Silas suffers remorse and kills himself. With the mystery satisfactorily resolved, Katherine and Robert find happiness together.