Mary Morstan has received a pearl in the post every year since her father’s disappearance; this leads Holmes and Watson to the truth about a secret pact between four convicts…

For years, a blackmailer has been preying on the weaknesses of others throughout London. When Holmes hears of the utter misery this mystery man is creating, he adopts a campaign…

Sherlock Holmes’ problem with disturbing dreams proves to be both an impediment and an aid in the search for a missing woman.