The document discusses mystery writing and different types of mysteries. It provides an overview of major mystery writers like Arthur Conan Doyle, who created Sherlock Holmes, as well as Dashiell Hammett and Alfred Hitchcock. Different genres of mystery like cozy mysteries, police procedurals, and hardboiled private eye stories are mentioned. The document also discusses how mystery is used in video games and animation like Scooby-Doo to engage audiences. It poses questions about how to go about writing mysteries and solving mysteries to drive plots forward.