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.
Sherlock Holmes
Dr. John H. Watson
Mrs. Hilda Courtney
Colonel Cavanaugh
Hamid
Inspector Hopkins
Ebenezer Crabtree
Julian 'Stinky' Emery
Evelyn Clifford
Mrs. Hudson
Commissioner of Scotland Yard
Tour Guide
Antique Shop Assistant (uncredited)
Detective at Murder Scene
Photographer
Joe Cisto
Pub Patron (uncredited)
Convict at Dartmoor Prison (uncredited)
Cab Driver (uncredited)
Alfred - Auction House Bookkeeper (uncredited)
Pub Patron (uncredited)
Minister's Wife (uncredited)
Pub Patron (uncredited)
Crabtree's Assistant at Auction (uncredited)
