Not only is Mallory Loehr a talented author, but she's also the Senior Vice President of Random House Books for Young Readers. She lives in Brooklyn, New York.

Thank you for watching my earth child. In an emergency, please call me. . . . So begins the mysterious note Polly and Sam discover in the woods near their grandparents' farm. There's no child in sight, but they do find a most unusual rock. Polly and Sam drag it home, but the strange-looking stone won't stay put! Before long, it is clear that something magical is happening to them again!