Join the world's greatest detective, Nate the Great, as he solves the mystery of the missing Earth Day robot in this long-running chapter book series that's a favorite for beginner readers! WILL THIS CASE ROLL AWAY? The Earth Day Fair is days away, but Nate's classroom project—a robot named Mr. Butler—has disappeared. Nate the Great and his dog, Sludge, take on the unusual case, and they are soon searching high and low in and around the school. Will Nate find the robot in time for the fair? Perfect for Common Core, the Nate the Great chapter book series will encourage children to problem-solve and learn about STEM topics, using logical thinking to solve mysteries!