Eight-year-old Jack and his little sister, Annie, are playing in the woods during their summer holiday, when they find a mysterious tree house full of books. But when they find themselves locked in a dungeon, Jack starts to wonder if they'll ever get home again .

Mary Pope Osborne is the author of over forty books for young people, including novels, picture books, biographies, mysteries, and retellings of fairy tales and myths. Mary was the president of the Author's Guild, the leading organization for professional writers in the United States for two years, and has won many different awards for her books.

She lives in New York City with her husband, Will, and their Norfolk terrier, Bailey - who sleeps on the top of Mary's desk every day while she writes.