Nick Grinde Director Boris Karloff Dr. Leon Kravaal Actor Roger Pryor Dr. Tim Mason Actor Jo Ann Sayers Judith Blair Actor Stanley Brown Bob Adams Actor John Dilson John Hawthorne Actor Hal Taliaferro Sheriff Stanton Actor Byron Foulger Dr. Bassett Actor Charles Trowbridge Dr. Harvey Actor Ernie Adams Pete Daggett Actor Karl Brown Screenwriter Benjamin H. Kline Cinematographer Al Clark Film Editing Lionel Banks Art Director