Number one adult bestselling author of MARLEY & ME: Life and Love with the World's Worst Dog, which inspired the bestselling middle-grade memoir MARLEY: A Dog Like No Other; and children's picture books BAD DOG, MARLEY! and A VERY MARLEY CHRISTMAS; has written the follow-up to his bestselling children's books. It's the first day of school and Cassie is all set to go...and so is Marley! Although he's told to stay, Marley digs a tunnel out of the backyard and sniffs his way to school. As he roams the halls looking for Cassie, he finds trouble instead. From wolfing down hot dogs in the cafeteria to setting free a bunch of mice in science class, lovable and rowdy Marley won't stop until he locates his best friend.