Set In Stone has been named the best children's book of the year for 2006 in the Costa Book Awards.
The book, written by Linda Newbery, is about an artist who is asked to tutor two girls. During the story they uncover a mystery at an old house.
Newsround Press Packers Nancy and Nathan helped pick the winning book from a shortlist of four books.
Set In Stone wasn't their favourite of the nominated books, but the other judges all thought it was the best.
The judges said about Set In Stone: "As beautifully crafted as one of the statues adorning the house in the story, this emotionally charged narrative will thrill all lovers of intelligent fiction."
The book's author Linda told Newsround: "I felt writing the book that there are a lot of twists and turns and surprises. I want the reader to try and work out the puzzles and the explanations and actually I want the reader to be wrong."
Other short-listed books
David Almond - Clay
Julia Golding - The Diamond of Drury Lane
Meg Rosoff - Just In Case
But Press Packer Nathan said that Set In Stone was classically written but it wasn't his kind of book.
Press Packer Nancy added: "Set In Stone has an very interesting prologue but I preferred another book, The Diamond Of Drury Lane."