In 1872, sixteen-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. Then, on the eve of their return to Montana, a group of whiskey traders slaughters forty Nakota. Mary sees the murderers take five Nakota women back to their fort. 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 brings out the worst and best in the cast of unforgettable characters and pushes the love between Farwell and Crow Mary to the breaking point.