Intent on painting the portrait of the Lakota chief Sitting Bull (Michael Greyeyes), Catherine (Jessica Chastain) travels from New York City to North Dakota. Merrily widowed and wealthy enough to roam with relative impunity, she’s unprepared for the complex politics of the region, managing to irritate the tribes-people, the United States Army (in the brusque form of a stellar Sam Rockwell) and the brutally bigoted townsfolk.