America of the last century. Northern Montana, where Indian tribes still live on their lands. In a fortified trading post, standing on the path of convoys with settlers heading to the west coast, lives the girl Sandrine - Bright Star, the daughter of a Frenchman and an Indian woman. She dreams of seeing the big world, which she knows about from books and stories of wagon train conductors. After living with relatives in Paris for several years and receiving an education there, she strives to return to her native land. Here, having gone through difficult trials and humiliation, overcoming the bitterness of disappointment, Sandrine regains the will to live and finds her love.