In the hills of Tennessee, Shane Carson, a gifted, nationally-recognized horseman, is living the good life. When a mysterious mustang shows up on his farm, Shane doesn't know how--or why--the horse appeared, but the horse's distinctive brand identifies her. She is one of the Spirit Horses, a rare, wild herd that runs free on the Shoshone reservation in Wyoming. Watched over for centuries in the tribe's ancestral valleys, these exquisite horses, according to belief, provide a link to the afterlife. When tragedy strikes in his life, Shane nearly loses his will to live--but for one promise he made to his young son: to return the mustang to her rightful home. On this bittersweet journey, Shane finds a world where tradition reigns, and ancient beliefs transcend modern logic. In this magnificent expanse of blue sky and wide open spaces, love is alive, but hate, intolerance, and greed threaten to close in. To make good on his vow, Shane must face the danger that threatens these horses, the tribe's legacy, and his destiny.