The Adventure of the Golden Pince-Nez by Arthur Conan Doyle

A reclusive professor’s secretary is found murdered in a locked room, with a pair of golden pince-nez glasses as the only clue. Holmes unravels the complex case, revealing a story of political vengeance, mistaken identity, and exile. The plot is layered and cerebral, with Holmes piecing together personality and motive from physical evidence. It’s a story of hidden passion and ideological commitment. One of the more intricate and introspective cases.