In 1840s England, acclaimed but overlooked fossil hunter Mary Anning (Kate Winslet) works alone on the rugged Southern coastline. With the days of her famed discoveries behind her, she now searches for common fossils to sell to tourists to support herself and her ailing mother. When a wealthy visitor entrusts Mary with the care of his wife Charlotte Murchison (Saoirse Ronan), she cannot afford to turn his offer down. Proud and relentlessly passionate about her work, Mary initially clashes with her unwelcome guest, but despite the distance between their social class and personalities, an intense bond begins to develop, compelling the two women to determine the true nature of their relationship.