Frances Dee
— Allison Lang
Brian Donlevy
— Duffy Giles
Charles Butterworth
— Felix
Helen Westley
— Mrs. Hargraves
Henry Stephenson
— Professor Jerome Hargraves
Sara Haden
— Henrietta Hargraves
Etienne Girardot
— Dr. Cotton
Gavin Muir
— Dr. Barth
Paul Stanton
— District Attorney
Julius Tannen
— City Editor
Nigel De Brulier
— Dr. Hall
Hilda Vaughn
— Bertha
Philip Sleeman
— Carl
William Ingersoll
— Judge
Paul McVey
— Coroner
Bruce Mitchell
— Police Sergeant
John Carradine
— Sanatorium Inmate (voice) (uncredited)
Don Rowan
— Juror (uncredited)
Harry Strang
— Court Attendant (uncredited)
Andrew Tombes
— Jury Foreman (uncredited)