The magic tree house takes Jack and his sister Annie to the Great Plains where they learn about the life of the Lakota Indians. Amazon.com Morgan Le Fey, a magical librarian from the time of King Arthur, has charged a brave young pair of children with the task of freeing an enchanted dog from a spell by collecting four gifts. In the 18th easy-to-read chapter book in Mary Pope Osborne's Magic Tree House series, eight-year-old Jack and seven-year-old Annie travel back almost 200 years to the Great Plains to find a "gift from the prairie blue." Along the way, Annie and Jack make friends with young Black Hawk, narrowly miss a buffalo stampede, and learn about how the Lakotas view the earth and their place in it. (Ages 8 to 12) About Magic Tree House series Magic Tree House is a book series for young children by Mary Pope Osborne. The series features two children, the bookworm Jack and his adventurous and imaginative younger sister Annie, who travel to historical places using a magic tree house. The magic tree house belongs to Morgan Le Fay who, in the series, is King Arthur's sister and a librarian. She uses the magic tree house to gather books from time and space. Jack and Annie travel by opening a book, pointing at a picture of a place and then wishing that they could go there. The magic tree house then spins around and magically they arrive at the location.