In 1872, 16-year-old Goes First, a Crow Native woman, marries Abe Farwell, a white fur trader. He gives her the name Mary, and they set off on the long trip to his trading post in the Cypress Hills of Saskatchewan, Canada. Along the way, she finds a fast friend; makes a lifelong enemy; and, despite learning a dark secret of Farwell’s past, falls in love with her husband. Then, on the eve of their return to Montana, a group of drunken whiskey traders slaughters 40 Nakota. Mary sees the murderers take five Nakota women back to their fort. She begs Farwell to save them, and when he refuses, she takes two guns, creeps into the fort and saves the women from certain death. Thus, she sets off a whirlwind of colliding cultures that pushes the love between Farwell and Crow Mary to the breaking point.