The #1 bestselling chapter book series of all time celebrates 25 years with new covers and a new, easy-to-use numbering system The magic tree house has returned and it's taking Jack and Annie back in time to Alaska, 1925. There they meet Balto, a jet-black Siberian husky destined to save victims of the diphtheria epidemic. But the trail isn't easy, and Balto is going to need Jack and Annie's help Formerly numbered as Magic Tree House #54, the title of this book is now Magic Tree House Merlin Mission #26: Balto of the Blue Dawn. 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 booksMerlin Missions: More challenging adventures for the experienced reader Super Edition: A longer and more dangerous adventure Fact Trackers: Nonfiction companions to your favorite Magic Tree House adventures Have more fun with Jack and Annie at MagicTreeHouse.com