Mary Downing Hahn is an American author known for her captivating children's and young adult literature, particularly in the genres of ghost stories and mysteries. Born on December 9, 1939, in Washington, D.C., she has written over 40 books, many of which have received critical acclaim and awards. Hahn's writing often explores themes of friendship, loss, and the supernatural, appealing to young readers. Some of her most popular works include Wait Till Helen Comes and The Old Willis Place. Her storytelling ability has made her a beloved figure in children's literature, inspiring generations of readers.