This is the biography that appears at the end of "The Seven Dials Mystery": "Agatha Christie is the world's best-Known mystery writer. Her books have sold over a billion copies in the English Language and another billion in 44 foreign languages. She is the most widely published author of all time in any language, outsold only by the Bible and Shakespeare. Her writing career spanned more than half a century, during which she wrote 80 novels and short story collections, as well as 14 plays, one of which, The Mousetrap, is the longest-running play in history. Agatha Christie also wrote under the pseudonym Mary Westmacott. As well, she wrote four non-fiction books including an autobiography and an entertaining account of many expeditions she shared with her archaeologist husband, Sir Max Mallowan. Agatha Christie died in 1976."