How to Go on an Unplanned Road Trip with Your Grandma: Grab a Suitcase: Fasten Your Seatbelt: G'ma's never conventional, so this trip won't be either. Use the Green Book: G'ma's most treasured possession. It holds history, memories, and most important, the way home. What Not to Bring: A Cell Phone: Avoid contact with Dad at all costs. Even when G'ma starts acting stranger than usual.8+ #1 New York Times bestselling author Nic Stone's irst middle-grade novel.