Holmes and Watson match wits with an opera star intent on blackmailing a king.

Holmes links a murder in a quiet English house to a Chicago gangster.

Holmes is called in when a top secret document is stolen from the British Foreign Office.

Holmes and Watson uncover a plot to marry a beautiful music teacher for her inheritance.

Holmes unravels a murder involving a locked room with no key, a domestic disagreement and a set of animal tracks.

Holmes is approached by Helen Stoner, who feels threatened by her domineering step-father, Dr Grimesby Roylott. Her sister died mysteriously just before her planned wedding, and Helen has heard again the curious whistle she first heard on the night of her sister's death. Holmes perceives great danger and lays a complicated plan to defeat the threat to the beautiful Helen.