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 readerSuper Edition: A longer and more dangerous adventureFact Trackers: Nonfiction companions to your favorite Magic Tree House adventuresHave more fun with Jack and Annie at MagicTreeHouse.com!