Though Fort Randall is an isolated outpost in 1876, Miriam Longstreet finds life there far more complicated than she expected when she reluctantly returns from boarding school. Harriet, her haughty mother, is an explosive laudanum addict, her free-spirited sister runs wild, and her father seems too occupied with his duties as commanding officer to notice. Miriam's independent streak rebels at Harriet's insistence that she abide by the narrow rules of army social structure. Seeking self-reliance, Miriam is confronted with difficult choices that could change her destiny. Determined to prove her maturity then join her friend Sarah in Denver, Miriam soon realizes Harriet's volatile behavior endangers her sister, and she sets her plans aside. She meets Private Jake Deakins. Drawn to Jake's raw masculinity, Miriam is unable to resist verbally sparring with him. Their attraction deepens into friendship despite the possibility their familiarity could be construed as misconduct. When eligible Lt. Robert Wood shows interest in Miriam, it seems the perfect alternative. Unaware that Robert's sole motivation is advancing his career, Miriam welcomes his courting. But Jake has introduced Miriam to a world unencumbered by artificial social rules. Rebelling, she befriends a laundress, explores class differences, convinces her father to allow a mixed-class party, campaigns for an all-post school, and confronts her parents. Her growing passion with Jake leads them to take risks that could ruin Jake's career. Meanwhile, Robert and Harriet plot to manipulate Miriam into marriage and Robert volunteers Jake for special duty in a life-threatening Indian fight. As Robert and Harriet become increasingly more maniacal, Miriam and Jake realize they are in love. Together, they face a raging blizzard, the possibility of Jake's court-martial, Harriet's growing abusiveness, and Robert's escalating deception and violence. The life-and-death choices they face could change everything.