Ellery Queen, Master Detective

Ralph Bellamy

Ellery Queen

Margaret Lindsay

Nikki Porter

Charley Grapewin

Insp. Queen

James Burke

Sgt. Velle

Michael Whalen

Dr. James Rogers

Marsha Hunt

Barbara Braun

Fred Niblo

John Braun

Charles Lane

Dr. Prouty

Ann Shoemaker

Lydia Braun

Marion Martin

Cornelia

Douglas Fowley

Rocky Taylor

Morgan Wallace

Zachary

Byron Foulger

Amos

Katherine DeMille

Valerie Norris

?

Peter Bronte

Doctor's Assistant (uncredited)