"A convicted thief in Dartmoor prison hides the location of the stolen Bank of England printing plates inside three music boxes. When the innocent purchasers of the boxes start to be murdered, Holmes and Watson investigate."
Basil Rathbone
as Sherlock Holmes
Nigel Bruce
as Dr. John H. Watson
Patricia Morison
as Mrs. Hilda Courtney
Frederick Worlock
as Colonel Cavanaugh
Harry Cording
as Hamid
Carl Harbord
as Inspector Hopkins
Holmes Herbert
as Ebenezer Crabtree
Edmund Breon
as Julian 'Stinky' Emery
Patricia Cameron
as Evelyn Clifford
Mary Gordon
as Mrs. Hudson
Ian Wolfe
as Commissioner of Scotland Yard
Leyland Hodgson
as Tour Guide
Marjorie Bennett
as Antique Shop Assistant (uncredited)
William H. O'Brien
as Detective at Murder Scene
Frank Baker
as Photographer
Sally Shepherd
as
Wallace Scott
as Joe Cisto
Jack Curtis
as Pub Patron (uncredited)
Cyril Delevanti
as Convict at Dartmoor Prison (uncredited)
Charlie Hall
as Cab Driver (uncredited)
Olaf Hytten
as Alfred - Auction House Bookkeeper (uncredited)
Frank Mills
Lillian Bronson
as Minister's Wife (uncredited)
Bobby Hale
Alexander Pollard
as Crabtree's Assistant at Auction (uncredited)
Roy William Neill
Director
Leonard Lee
Screenplay
Frank Gruber
Adaptation
Arthur Conan Doyle
Story
Saul A. Goodkind
Editor
Edward R. Robinson
Set Decoration
Milton Rosen
Music Director
Howard Benedict
Executive Producer
Jack Pierce
Makeup Department Head
Maury Gertsman
Director of Photography
Jack Otterson
Art Direction
Producer
Russell A. Gausman
Carmen Dirigo
Hairstylist
Vera West
Costume Design
Bernard B. Brown
Sound Director
Martin Obzina