William Gargan

~ as ~

Ellery Queen

Margaret Lindsay

~ as ~

Nikki Porter

Charley Grapewin

~ as ~

Inspector Richard Queen

Gale Sondergaard

~ as ~

Mrs. Van Dorn

Gilbert Roland

~ as ~

Paul Gilette

Sig Ruman

~ as ~

Heinrich, Spy Leader

James Burke

~ as ~

Police Sergeant Velie