Conan Doyle (1859— 1930), the author of this book, is known as "the father of English detective stories" and is still one of the best-selling detective story writers in China and even in the world. When I was young, I studied at Aiyubao Medical University. After graduation, I practiced medicine. After work, I became interested in detective stories and began to try to write. The first detective novel "A Study of Blood Characters" was finally published after many twists and turns, and his writing career began. Two years later, he published Four Signatures, which became an instant hit. 189 1 year, he gave up medicine and became a full-time detective novel writer. Since then, his creation has been out of control, and he has written a series of wonderful detective novels. For example, the scandal in Bohemia, the Red Hair Society, the Five Orange Nuclei and so on. In just a few years, Doyle's reputation is in full swing and his economic situation has greatly improved. So he was born in 1894 and decided to wash his hands of it. In the novel The Last Case, Holmes fell off a cliff and died. Unexpectedly, his readers were greatly dissatisfied with the ending, even angry. They are used to reading the stories of Sherlock Holmes often. They don't believe that this great detective will die like this. Doyle was deeply moved and encouraged by the reader's protest. As a response to the readers' eager hope, he took up the pen of imagination and conceived a new case, which brought Holmes back from death in the case of an empty house and satisfied the readers' wishes. Later, he wrote The Hound of the Baskerville, Return, uncanny valley, Adventure History, Memoirs, Last Greetings and other works. By 1929, all his detective novels had been compiled into The Complete Works of Sherlock Holmes (up and down) and published in Britain. On July 7th of the following year, Conan Doyle died at the age of 7 1.