Another wonderful book from Rebecca Stead. She hits the mark so well with her characters and stories -- it's remarkable that they resonate so well with me as an adult, though they are aimed at children. (This is one of the hallmarks of the Newbery winners, no doubt.) 
 I loved Liar & Spy more, but there's so much great stuff in here, too, especially for fans of A Wrinkle in Time.