Roy William Neill
Director
Bertram Millhauser
Writer
Bertram Millhauser
Screenplay
Lynn Riggs
Screenplay
Bertram Millhauser
Original Story
Lester White
Director of Photography
Howard Benedict
Associate Producer
Roy William Neill
Producer
Frank Skinner
Music
Otto Ludwig
Editor
Jack Otterson
Art Direction
Russell A. Gausman
Set Decoration
Vera West
Costume Design
William Tummel
Assistant Director
Arthur Conan Doyle
Characters
Basil Rathbone
Sherlock Holmes
Nigel Bruce
Doctor Watson
Marjorie Lord
Nancy Partridge
Henry Daniell
William Easter
George Zucco
Heinrich Hinckel aka Richard Stanley
John Archer
Naval Lt. Pete Merriam
Gavin Muir
Mr. Lang, government agent
Edmund MacDonald
Detective Lt. Grogan
Don Terry
Howe
Mary Gordon
Mrs. Hudson
Bradley Page
Cady
Clarence Muse
George
Mary Forbes
Mrs. Pettibone
Holmes Herbert
Mr. Ahrens
Thurston Hall
Sen. Henry Babcock
Ian Wolfe
Antiques Store Sales Clerk
John Burton
Army Inspector (uncredited)
Gerald Hamer
Alfred Pettibone
Gilbert Emery
Sir Henry Marchmont (uncredited)
Margaret Seddon
Miss Pringle (uncredited)
Mary Field
Party Pianist (uncredited)
Colin Kenny
Hotel Doorman (uncredited)
Caroline Frances Cooke
Mrs. Ruxton
