Basil Rathbone
Sherlock Holmes
Acting
Nigel Bruce
Doctor Watson
Acting
Marjorie Lord
Nancy Partridge
Acting
Henry Daniell
William Easter
Acting
George Zucco
Heinrich Hinckel aka Richard Stanley
Acting
John Archer
Naval Lt. Pete Merriam
Acting
Gavin Muir
Mr. Lang, government agent
Acting
Edmund MacDonald
Detective Lt. Grogan
Acting
Don Terry
Howe
Acting
Mary Gordon
Mrs. Hudson
Acting
Bradley Page
Cady
Acting
Clarence Muse
George
Acting
Mary Forbes
Mrs. Pettibone
Acting
Holmes Herbert
Mr. Ahrens
Acting
Thurston Hall
Sen. Henry Babcock
Acting
Ian Wolfe
Antiques Store Sales Clerk
Acting
John Burton
Army Inspector (uncredited)
Acting
Gerald Hamer
Alfred Pettibone
Acting
Gilbert Emery
Sir Henry Marchmont (uncredited)
Acting
Margaret Seddon
Miss Pringle (uncredited)
Acting
Mary Field
Party Pianist (uncredited)
Acting
Colin Kenny
Hotel Doorman (uncredited)
Acting
Caroline Frances Cooke
Mrs. Ruxton
Acting