If it were up to Mattie Markham, there would be a law that said your family wasn't allowed to move in the middle of the school year. After all, sixth grade is hard enough without wondering if you'll be able to make new friends or worrying that the kids in Pennsylvania won't like your North Carolina accent. But when Mattie meets her next-door neighbor and classmate, she begins to think maybe she was silly to fear being the "new girl." Agnes is like no one Mattie has ever met -- she's curious, hilarious, smart, and makes up the best games. If winter break is anything to go by, the rest of the school year should be a breeze. Only it isn't, because when vacation ends and school starts, Mattie realizes something: At school Agnes is known as the weird girl who no one likes. All Mattie wants is to fit in (okay, and maybe be a little popular too), but is that worth ending her friendship with Agnes?