Separated as toddlers in the Catholic orphanage where their mother had left them, Leah Broome has spent her young life craving the love of her twin sister, Lara. When a letter from the convent announces Lara's death and the impending arrival of her daughter, Prairie Rose, Leah prepares to welcome the girl as if she were Lara herself. Arriving in town to meet his daughter on the train, Tom Woden claims to be Prairie's father. The girl, however, is half Wind River Shoshone, restricting Tom's paternity claim to the dates of his marriage to Lara. Uncomfortable with his intimate knowledge of the sister whose friendship she has coveted, Leah confronts her competitor for her niece's affections.