The #1 bestselling Magic Tree House series is ready to whisk you away across the world with Jack and Annie--this time to rescue little horses in Mongolia! Perfect for chapter book readers. Jack and Annie hear the cry of a golden eagle when the magic tree house spins them back in time to a nature reserve for horses! As Eco-Volunteers, Jack and Annie find themselves alone in Mongolia, on a plain in the middle of the night. Under the light of a full moon, they ride mountain bikes across the land, summon a mysterious helper, and try desperately to save wild horses whose very existence is in danger. Can Jack and Annie protect the last of the little horses?  Did you know that there's a Magic Tree House book for every kid? Magic Tree House: Perfect for readers who are just beginning chapter books Merlin Missions: More challenging adventures for the experienced reader Fact Trackers: Nonfiction companions to your favorite Magic Tree House adventures Graphic Novels: Relive the original adventures brought to life with art by Kelly & Nichole Matthews