The #1 bestselling chapter book series of all time celebrates 25 years with new covers and a new, easy-to-use numbering system! Merlin the magician and Morgan le Fay have disappeared, and in order to find them, Jack and Annie journey with their friends Teddy and Kathleen to the Land-Behind-the-Clouds, a frozen kingdom of ice and snow. There they must overcome their fears and solve the Ice Wizard's riddle, because if Jack and Annie don't complete their mission in time, Merlin and Morgan will disappear forever! Formerly numbered as Magic Tree House #32, the title of this book is now Magic Tree House Merlin Mission #4: Did you know that there’s a Magic Tree House book for every kid? Magic Tree House: Adventures with Jack and Annie, perfect for readers who are just beginning chapter books Super Edition: A longer and more dangerous adventure Fact Trackers: Nonfiction companions to your favorite Magic Tree House adventures