Agatha Christie. 2 novels: The Mysterious Affair at Styles and The Secret Adversary

Agatha Christie (15 September 1890 – 12 January 1976), was an English crime writer of novels, short stories and plays. She also wrote romances under the name Mary Westmacott, but is best remembered for her 80 detective novels and her successful West End theatre plays. Her works, particularly those featuring detectives Hercule Poirot and Miss Jane Marple, have given her the title the 'Queen of Crime' and made her one of the most important and innovative writers in the development of the genre.

— Excerpted from Wikipedia, the free encyclopedia.