The Magic Tree House look now clearly delineates a reading journey through three distinct lines: Magic Tree House titles for beginning chapter book readers, Merlin Missions for more advanced readers, and Fact Trackers for non fiction fans. By renumbering the 55 fiction titles in two groups (plus a Super Edition!), we are encouraging readers to stay with their favorite series longer, giving them a sense of accomplishment as they move from the classic adventures into the Merlin Missions.