Sir Arthur Igneyshus Conan Doyle (22.05.1859 — 07.07. 1930) was an English writer, author of numerous adventure, historical, journalistic, fiction and humorous works.
The Sign of Four is a detective story of young Marry Morsten, who asked Sherlock Holmes to help her unravel the mistery. During the last six years, once а year, Marry is sent an anonymous parcel with a wonderful pearl. Her father disappeared ten years ago. Are these two events have a link?