Addie is a Frenchwoman born in 1691 who strikes a desperate bargain for eternal life to avoid an arranged marriage. The cost of her immortality is a curse that causes everyone to forget her the moment she leaves their sight. Spends centuries trying to survive as a ghost in the physical world, she develops a fierce resilience and a profound appreciation for art. She discovers that while she cannot leave physical marks, she can indirectly inspire artists to record her existence.

Henry is a sensitive, intellectually curious bookseller in his late twenties living in New York City. He struggles with depression and a persistent feeling of inadequacy following a severe romantic rejection. His quiet life shifts completely when he surprisingly retains his memory of Addie, making him her only true connection to the modern mortal world.

Luc is an ancient, supernatural entity of the dark who answers prayers made after sundown. He takes the physical form of a handsome, green-eyed man drawn directly from Addie's youthful sketchbook. Possessive and manipulative, he views his supernatural bargains as a game and seeks to break Addie's spirit so she will voluntarily surrender her soul to him.

Estele is an elderly woman who lives on the fringes of Addie's rural 18th-century French village. She communes with nature and worships the old gods, serving as an example of independence for the young Addie. She imparts crucial spiritual rules, particularly the explicit warning never to pray to the gods who answer after dark.

Remy is a young, educated man from a provincial French village who moves to Paris to experience a wider world. He shares Addie's restless spirit and desire to escape rural life, though his gender grants him the freedom and education that she was systematically denied.

Bea is a graduate student and one of Henry's closest friends in New York. She is currently working on an art history thesis regarding mysterious, centuries-spanning portraits of a woman with a distinct pattern of freckles.

Robbie is an actor and a close friend of Henry, though their history as former romantic partners leaves a lingering tension between them. He is protective of Henry and skeptical of sudden changes in his life.

Tabitha is Henry's recent ex-girlfriend. Her decisive rejection of his marriage proposal sends Henry into a deep emotional spiral that drastically alters the trajectory of his life.

Toby is a struggling musician living in modern-day New York City. He unknowingly collaborates with Addie, who serves as his muse and guides his hands on the piano to write melodies she cannot physically record herself.

Sam is an abstract painter in modern New York City. Like Toby, she shares brief intimacies with Addie, and her artistic sensibilities are heavily influenced by Addie's presence.

A skilled woodworker from Villon-sur-Sarthe. He unknowingly sparks his daughter's profound wanderlust by bringing her along on trips to sell his carvings in the bustling city of Le Mans.

A traditional woman of 18th-century rural France. She expects Addie to conform to the standard path of marriage and motherhood, consistently pressuring her daughter to abandon her daydreams.

A recent widower in Villon-sur-Sarthe with three small children. He represents the stifling, loveless domestic trap that Addie desperately wants to escape.

Henry's older brother, who works as a highly successful head surgeon. His professional stability acts as a constant point of comparison for Henry's more scattered career path.

Henry's younger sister. She provides a grounded familial connection for Henry in the city, frequently checking in on him.