When Dr. Pieter Fales' patients start receiving ominous letters and getting murdered by an unknown black-clad assailant, he and his daughter both come under suspicion.
| Actor | Role |
|---|---|
 Klaus KinskiDr. Pieter Fales | Dr. Pieter Fales |
| DDonna WilkesAlison Fales | Alison Fales |
 Marianna HillJulie | Julie |
 Craig WassonDoug | Doug |
 Richard HerdDonahue | Donahue |
 Joe RegalbutoJake | Jake |
 Christopher LloydGilbert | Gilbert |
 Flo LawrencePat | Pat |
| KKiva LawrenceRosemary | Rosemary |
| CClaude DuvernoyFrançoise | Françoise |
| CCindy DonlanSally | Sally |
 Jon GreeneArchie | Archie |
| DDavid AssaelBarney | Barney |
| RRichard BalinFreddy | Freddy |
| FFredric CookWilly | Willy |
| KKathy GarrickMaxine | Maxine |
| GGracia LeeBruce | Bruce |
| TTobar MayoFritz | Fritz |
| JJonathon MillnerFritz's Friend | Fritz's Friend |
| FFrances E. NealyHousekeeper | Housekeeper |
| KKimberly JensenGirl on Motorbike | Girl on Motorbike |
| JJay MayBoy on Motorbike | Boy on Motorbike |
| CCindy RiegelSecretary (uncredited) | Secretary (uncredited) |
 Tony SwartzBartender (uncredited) | Bartender (uncredited) |