In January 1856 in rural Schoharie County in upstate New York, Abigail (Katherine Waterson) and her husband Dyer (Casey Affleck) live an isolated life in the country working as farmers. They are both devastated by the recent loss of their young daughter Nellie.A new similarly childless couple moves into the cabin beside them. Abigail is immediately entranced by Tallie (Vanessa Kirby), the wife, and the two women form a quick and deep friendship. Abigail confides to Tallie that her marriage with Dyer is based on practicality, not romance while Tallie reveals that her husband Finney (Christopher Abbott) can be quarrelsome and controlling.For Abigail's birthday, Tallie buys her an atlas map of the state that she had longed for. When Tallie is returning home from the birthday visit she is caught in a violent snowstorm that nearly kills her. Her husband takes her away to recuperate, and when she returns it is spring and Tallie resumes her visits to Abigail.Eventually Tallie reveals to Abigail that she only dreams of being with her. Abigail feels similarly and the two kiss. They begin a sexual affair behind their husbands backs. Dyer, who has become increasingly emotional since their child's death, is upset at the time that Abigail spends with Tallie. At the same time, Tallie's husband becomes similarly jealous at the hours she is spending away from him.Finney eventually asks Abigail and Dyer to dinner where he uncomfortably brings up their lost child and Abigail notices bruises on Tallie's neck. Afterwards Tallie doesn't visit for a week. Abigail finally goes in search of her and finds her rented house empty with only a bloody kerchief left behind. Though she suspects mischief, she eventually receives a letter from Tallie informing her she has moved 85 miles away.Abigail insists on going to see Tallie and Dyer reluctantly complies. However by the time they arrive Tallie is dead which Finney claims is from diphtheria.Abigail returns to her unhappy life on the farm. She and Dyer continue to work together but grow more emotionally estranged. To comfort herself, Abigail imagines murdering Finney one day and tries to picture Nellie and Tallie comforting themselves in the afterlife.