Dame Agatha Mary Clarissa Christie (15 September 1890 – 12 January 1976) was an English writer of crime stories. Her books are very famous all over the world, and she sold more than 4 billion books around the world. Only William Shakespeare has sold more books. Also, her books are written in more languages than any other writer's books. People can read them in 103 different languages. Her stories are about murders and finding out who did them. It is hard to find that person. There is a detective who tries to catch the bad person. People like reading her books because they can try to find the answer, too. Reading these books is like playing a game. The most well-known characters in her books are Miss Marple and Hercule Poirot. Miss Marple is an old English lady, and she talks to everyone. People do not think she is smart, but she always finds the bad person. She uses logic to find out who is guilty of the murder. Hercule Poirot is a strange man, a private detective from Belgium who lives in London. He likes to find out who did the murder by thinking about all the evidence. The stories of Poirot and Miss Marple were made into many TV shows and movies.