The 2013 Guardian Children's Fiction Prize...
...has been awarded to Rebecca Stead, for Liar and Spy:
"Liar & Spy is an incredibly sensitive book. Its central characters are all children who have complexities in their lives which they are dealing with," said Julia Eccleshare, Guardian children's books editor and chair of the judges. "It's a novel about how children have to navigate the world, and it has an open-handedness which means that readers may be surprised as to where it finishes."
If you haven't read it, the first chapter is available online!