A mad doctor is determined to take revenge on the family he believes is responsible for his daughter's death.
| Actor | Role |
|---|---|
 Warner OlandDr. Boris Karlov | Dr. Boris Karlov |
 June CollyerKitty Conover | Kitty Conover |
 Lloyd HughesPrince Nicholas Petroff | Prince Nicholas Petroff |
 Clara BlandickAunt Abbie | Aunt Abbie |
 Hale HamiltonMartin Kent | Martin Kent |
 Wallace MacDonaldPrince Gregor Petroff | Prince Gregor Petroff |
 George FawcettGeneral Petroff | General Petroff |
 Florence LakeAnya Karlov | Anya Karlov |
 Mischa AuerPeter | Peter |
 Ernest HilliardPrince Ivan Petroff | Prince Ivan Petroff |