Violet Hunter has been offered the role of governess at an estate in Hampshire but the employer insists that for the role she will be obliged to cut her hair short. Her perturbation at this causes her to seek Sherlock Holmes's advice.

An unsavory gang kidnaps a Greek interpreter and forces him to relate their demands to an abductee who knows only the Greek tongue.

When a notorious retired builder is found dead, his recently-named heir is the prime suspect.

Sherlock Holmes is contacted by Dr Trevelyan whose medical practice was set up and paid for by Mr Blessington who lives on the premises. Of late Mr Blessington has had spells of intense anxiety. Dr Trevelyan fears for his health and life.

What seems at first to be a harmless prank played upon a red-headed man is soon revealed to be much more: a sinister scheme devised by the Napoleon of Crime.

Holmes and Watson travel to Europe to escape Moriarty's vengeance.