Arthur and his friends go to Camp Meadowcroak, where everything is a competition between girls and boys. The two teams refuse to collaborate, but when a rival camp plays a spooky prank on them, they realize they must work together to beat the rival camp in the annual scavenger hunt. Buster falls behind with his schoolwork, and is threatened with repeating third grade if he does not improve. Arthur, Muffy, and Francine tutor him, but he struggles to pay attention.