In 1880, Sir Robert Cargrave, a London physician known for his experimental work in paralysis treatment, is summoned to Gorslava by the mysterious Baron Sardonicus—who is now married to Cargrave's former wife, Maude—to treat his disfigurement. When Cargrave arrives, he finds the masked baron is a cruel sadist who has threatened to harm Maude if he is not successfully cured.
| Actor | Role |
|---|---|
 Ronald LewisSir Robert Cargrave | Sir Robert Cargrave |
 Audrey DaltonMaude Sardonicus | Maude Sardonicus |
 Guy RolfeBaron Sardonicus | Baron Sardonicus |
 Oskar HomolkaKrull | Krull |
 Vladimir SokoloffHenryk Toleslawski | Henryk Toleslawski |
 Erika PetersElenka | Elenka |
| LLorna HansonAnna | Anna |
| CConstance CavendishMrs. Higgins (uncredited) | Mrs. Higgins (uncredited) |
| JJames ForrestGeoffery Wainwright (uncredited) | Geoffery Wainwright (uncredited) |
| TTina WoodwardThe Girl (uncredited) | The Girl (uncredited) |
| MMavis Neal PalmerHead Nurse (uncredited) | Head Nurse (uncredited) |
| CCharles H. RadilakStationmaster (uncredited) | Stationmaster (uncredited) |
| DDavid JantiJanku (uncredited) | Janku (uncredited) |
| FFranz RoehnGravedigger (uncredited) | Gravedigger (uncredited) |
 Annalena LundFirst Girl (uncredited) | First Girl (uncredited) |
| IIlse BurkertSecond Girl (uncredited) | Second Girl (uncredited) |
 William CastleSelf (uncredited) | Self (uncredited) |