Quinny has a lot to say. Hopper gets to the point. Quinny has one speed: very, very, extra-very fast. Hopper is slow and careful. Quinny has big ideas. Hopper has great solutions. Quinny and Hopper couldn't be more different. They are an unstoppable team. But when summer ends, things suddenly aren't the same. Can Quinny and Hopper stay best friends in the face of stylish bullies, a killer chicken, and the Third Grade Rules—especially the one that says they aren't allowed to be friends?