Bonita is used to spending the day carrying her elegant mistress to fiestas and being cared for in a safe, snug barn, but when shots are fired at the Alamo, Bonita's perfect life at the ranch is gone forever.
Sierra, a feisty filly born into a herd of free horses on the plains of the untamed American West, finds her place in the herd tested when a new stallion steps up and becomes the new leader.