The document discusses some of the most influential early mystery novelists, including Edgar Allan Poe, Arthur Conan Doyle, and Agatha Christie. It notes that Poe is considered one of the founders of both the mystery and horror genres. It describes how Doyle's Sherlock Holmes stories immersed readers in solving mysteries alongside Holmes and Watson. Finally, it states that Agatha Christie is one of the best-selling authors of all time and was among the first to use plot twists and red herrings in mysteries.