Ralph Bellamy
Ellery Queen
Acting
Margaret Lindsay
Nikki Porter
Acting
Charley Grapewin
Insp. Queen
Acting
James Burke
Sgt. Velle
Acting
Michael Whalen
Dr. James Rogers
Acting
Marsha Hunt
Barbara Braun
Acting
Fred Niblo
John Braun
Directing
Charles Lane
Dr. Prouty
Acting
Ann Shoemaker
Lydia Braun
Acting
Marion Martin
Cornelia
Acting
Douglas Fowley
Rocky Taylor
Acting
Morgan Wallace
Zachary
Acting
Byron Foulger
Amos
Acting
Katherine DeMille
Valerie Norris
Acting
Peter Bronte
Doctor's Assistant (uncredited)
Acting
Jack Cheatham
Desk Sergeant (uncredited)
Acting
Arthur Millett
Elevator Guard (uncredited)
Acting
Frank O'Connor
Ambulance Driver (uncredited)
Acting
Lee Phelps
Flynn (uncredited)
Acting
Jack Rice
Rogers' Assistant (uncredited)
Acting
Alan Ladd
Elevator Passenger (uncredited) (unconfirmed)
Acting