A card cheat is threatened with exposure into joining a criminal enterprise that Sherlock Holmes believes is controlled by Professor Moriarity.
Arthur Wontner
as Sherlock Holmes
Ian Fleming
as Dr. John Watson
Minnie Rayner
as Mrs. Hudson
Leslie Perrins
as Ronald Adair
Jane Welsh
as Kathleen Adair
Norman McKinnel
as Prof. Robert Moriarty / Col. Henslowe
William Fazan
as Thomas Fisher
Sydney King
as Tony Rutherford
Philip Hewland
as Inspector Lestrade
Gordon Begg
as Marston, the butler
Louis Goodrich
as Colonel Sebastian Moran
Harry Terry
as No. 16
