A friend asks Doctor Watson to find the drug-addicted man of a friend. He has been missing for a few days. Doctor Watson finds him in an opium den. To Watson's surprise, he also encounters his friend Sherlock Holmes there. Holmes is searching for the well-known gentleman Mr. St. Clair. He has likely been murdered. Holmes and Watson suspect a beggar with a disfigured face. Finally, the door of the opium den opens. A hunchbacked man stumbles out. He turns into a side alley. Watson follows him. Then the hunchback looks around. He straightens up and starts laughing loudly. "Watson! What a coincidence to meet you in the den. What did you think? That I smoke opium?".