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?