After being rescued as infants from a sinking ocean liner in 1914, Marian and Jamie Graves are raised by their dissolute uncle in Missoula, Montana. There, Marian commences her lifelong love affair with flight. At 14, she drops out of school and finds an unexpected and dangerous patron in a wealthy bootlegger who provides a plane and subsidizes her lessons, an arrangement that will haunt her for the rest of her life, even as it allows her to fulfill her destiny: circumnavigating the globe by flying over the North and South Poles. A century later, Hadley Baxter is cast to play Marian in a film that centers on Marian's disappearance in Antarctica. Her immersion into the character of Marian unfolds alongside Marian's own story, as the two women's fates collide.