One of Agatha Christie's most popular sleuths, elderly spinster and deceptively mild-mannered Miss Jane Marple appeared in 12 books and 20 short stories and has been portrayed multiple times on screen. Miss Marple acts as an amateur consulting detective, solving mysteries by observing human nature in the small town of St. Mary Mead and applying what she's learned to the world at large. She. Some of the most popular Miss Marple books include The Moving Finger, The Caribbean Mystery, and The Body in the Library.