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
