Max loves his grandpa and Grandpa loves Max. So when Max has to say goodbye to Grandpa at the end of his trip, Grandpa reminds Max that the same moon that is above them at Grandpa's house is the very same moon that will follow him all the way home. On the way home, Max watches as the moon tags along and he thinks about his Grandpa. When the sky darkens and the moon disappears behind the cloud, Max worries that the moon did not follow him home after all. It still hasn't reappeared by the time he gets home and Max feels sad and lonely. Then the cloud parts and the moon appears!