The Adventure of the Veiled Lodger

Mrs. Merrilow of South Brixton's lodger, Mrs. Ronder, is usually very quiet. The woman never shows her face and with reason, for it is severely mutilated – Mrs. Merrilow only saw it once. But lately she has started shouting in her sleep and her health has been going downhill. She refuses help from anyone, except Holmes, and charges Mrs. Merrilow, when she brings her case to him, to mention "Abbas Parvas". The detective knows just what that means.
"The Adventure of the Veiled Lodger" is part of "The Case-Book of Sherlock Holmes".
Sir Arthur Conan Doyle (1859-1930) was born in Scotland and studied medicine at the University of Edinburgh. After his studies, he worked as a ship’s surgeon on various boats. During the Second Boer War, he was an army doctor in South Africa. When he came back to the United Kingdom, he opened his own practice and started writing crime books. He is best known for his thrilling stories about the adventures of Sherlock Holmes. He published four novels and more than 50 short-stories starring the detective and Dr Watson, and they play an important role in the history of crime fiction. Other than the Sherlock Holmes series, Doyle wrote around thirty more books, in genres such as science-fiction, fantasy, historical novels, but also poetry, plays, and non-fiction.