Marian is an independent aspiring aviator growing up in Missoula, Montana, during the Prohibition era. Raised by her uncle, she fiercely guards her autonomy and resents any form of debt or obligation. Her absolute determination to become a pilot drives her to defy the gender expectations of her time and secure her own aircraft.

Hadley is a famous, wealthy Hollywood actor reeling from a public breakup and career crisis. Orphaned at a young age, she feels trapped by the artificiality of her career and personal life. Taking on the role of Marian Graves in an upcoming biographical film represents her attempt to seize agency and redefine her trajectory in the film industry.

Jamie is Marian's twin brother, a compassionate boy who eventually pursues a career as a painter. Deeply sensitive to the world around him, he is a vegetarian who struggles to reconcile his love for living things with the harshness of human society. He provides Marian with a vital emotional anchor during their unconventional childhood.

Barclay is a wealthy bootlegger and local gangster operating in Montana during Prohibition. He becomes fixated on a young Marian, using his vast resources to act as her benefactor. His obsession manifests as a desire to control her entirely, masking his manipulative nature behind the guise of generosity.

Caleb is a fiercely independent young man raised by a sex worker in Missoula. He bonds with the Graves twins over their shared unconventional upbringings and love of the Montana wilderness. He and Marian share a lifelong connection defined by their mutual refusal to be tied down by traditional expectations.

Trout is a skilled pilot who smuggles alcohol for Barclay Macqueen. Recognizing Marian's natural aptitude for aviation, he becomes her first flying instructor. He happily defies the sexist norms of the era to teach a young girl how to fly, imparting crucial technical skills and life advice.

Ruth is a brash, confident, and highly skilled navigator who works alongside Marian during World War II. Despite the restrictive social expectations of the era, she maintains a fearless attitude toward her dangerous work and her personal life. She forms a deep, meaningful bond with Marian while stationed in Britain.

Eddie is a skilled navigator chosen by Marian to accompany her on her ambitious journey across the North and South Poles. As a gay man living in mid-20th-century America, he uses his marriage of convenience to Ruth to survive in a prejudiced society. He carries deep psychological scars from his wartime experiences.

Addison is Marian and Jamie's father, a former ship captain whose life is defined by a public disgrace following a maritime disaster. Unable to cope with his shame and failure, he abandons his infant children with his brother in Montana, casting a shadow of abandonment over their lives.

Redwood is the earnest and occasionally elusive producer of the film based on Marian Graves's life. As the grandson of a wealthy shipping magnate, his family history connects indirectly to the Graves twins. He presents a complicated romantic possibility for Hadley during the film's production.

Alexei is a married Hollywood talent agent who represents Hadley's former co-star, Oliver. He functions as an idealized romantic interest for Hadley, often prioritizing his established family and career over her erratic life in the public eye.

Wallace is Marian and Jamie's uncle, a painter of natural scenery living in Missoula, Montana. Tasked with raising his niece and nephew after his brother's disgrace, he is an unconventional guardian who struggles with alcoholism and gambling debts, allowing the twins immense freedom to roam the wilderness.

Sarah is the daughter of a wealthy meatpacking businessman in Seattle. She forms an intense early romance with Jamie Graves, drawn to his artistic talent and compassion, though their relationship is severely tested by their differing backgrounds and her father's disapproval.

Oliver is Hadley's former co-star in the Archangel film franchise. Their highly publicized relationship delighted fans but felt performative and constricting to Hadley, ultimately dissolving amid mutual infidelities and intense media scrutiny.

Lloyd is a wealthy American shipping magnate who builds the Josephina Eterna in a bid to revive his company's success. He promotes his old friend Addison Graves to captain, though their relationship fractures amid personal grief and war profiteering.

Mathilda is Lloyd Feiffer's wife, a woman burdened by her husband's infidelities and immense personal grief. She blames herself for a maritime disaster due to a botched ship christening ceremony, carrying this guilt for decades.

Annabel is Marian and Jamie's mother. Burdened by a traumatic past of abuse and severe mental health struggles, she marries Addison Graves but suffers from profound post-natal depression, unable to cope with the demands of motherhood.

Adelaide is a friend of Carol Feiffer who claims to have met Marian Graves during her childhood. She becomes a valuable resource for Hadley, possessing decades' worth of letters to and from Marian that provide deeper insight into the aviator's private life.

Carol is the author of the biography on which Hadley's upcoming film is based. She is earnest and excited about the project, sharing her extensive research into Marian's life with the film's cast and crew.

Mitch is Hadley's uncle and former guardian, a television director who seemed ill-equipped to raise a child. He helped Hadley discover her talent for acting before his untimely death from an overdose.

Sir Hugo is Hadley's neighbor and a film producer. He helps her deal with the toxic online reaction to her public scandal and introduces her to the Marian Graves biographical project, opening a new path for her career.