The Dark Mirror on AllMovie

The Dark Mirror is the first of two Hollywood films of that title dealing with "doppelganger" twin sisters. The later film, made in 1946, concerns a murder committed by one of the siblings. The earlier Dark Mirror, lensed in 1920, is constructed more along Count of Monte Cristo or Prince and the Pauper lines. Dorothy Dalton does double duty as a girl of the slums and her high-society identical twin. It is inevitable that the twins will somehow trade places around Reel Three. The Dark Mirror is based on a story by Louis Joseph Vance, of Lone Wolf fame.