Casey is a 31-year-old struggling writer and waitress working at a high-end Boston restaurant called Iris. She lives in a rented potting shed and faces crippling student loan debt. The sudden loss of her mother deeply informs her daily life, causing severe anxiety and a prolonged period of writer's block on the novel she has been working on for six years.

Oscar is a 47-year-old successful author and widower raising two young sons. He left his position as a university professor to write full-time and care for his family after his wife's passing. His established career and comfortable home offer a sense of stability that contrasts directly with the typical artistic struggle.

Silas is a high school teacher and writer who connects with Casey at a literary gathering. He shares a quiet, understanding demeanor and is familiar with personal loss, having lost his sister. He drives a run-down car and shares an apartment with roommates, mirroring the financial realities of an aspiring artist.

Muriel is a fellow writer and Casey's most supportive friend. While many of Casey's peers have abandoned their artistic ambitions for traditional careers, Muriel remains deeply involved in the literary scene. She provides practical industry advice, sets up social opportunities, and offers a steadying presence.

Caleb is Casey's brother, who lives far away and was sent to boarding school during their childhood. He processes the loss of their mother differently than Casey does. He maintains contact with his old college friends and tries to provide logistical support to his sister when he visits.

Adam is a former college friend of Caleb who acts as Casey's landlord in Brookline. He rents her a small potting shed on his property. He views Casey's lifestyle choices with a mix of curiosity and condescension, failing to understand her financial struggles.

Casey's mother is a vibrant figure whose sudden death from an apparent embolism leaves her daughter unmoored. She lived in Cuba during her youth, which directly inspired Casey's novel. Her past choices, including a temporary departure from the family for an affair, heavily influenced Casey's emotional development.

Rob is Casey's father and a former high school math teacher and golf coach. He obsessively trained Casey to become a top-tier junior golfer, straining their relationship. A disturbing incident involving his voyeuristic behavior at his school led to his early retirement and Casey's permanent estrangement from him.

Luke is a poet who attends the Red Barn writer's residency during the same summer as Casey. He engages in a passionate, secretive summer romance with her shortly after her mother's death. He proves to be emotionally unavailable and hides significant details about his personal life.

Harry is a fellow server at Iris who bonds with Casey over the stresses of the restaurant industry. They enjoy smoking, gossiping, and eating together during the chaotic shifts, providing a temporary escape from their outside worries.

Marcus is the manager at the high-end restaurant Iris. He oversees the competitive floor staff and handles scheduling, deliberately trying to keep chatty servers apart during busy rushes. He frequently brushes off staff complaints.

Clark is a chef at Iris. He holds a grudge against Casey following an inappropriate advance he made toward her in the restaurant's walk-in refrigerator, resulting in a hostile and retaliatory work environment.

John is Oscar's five-year-old son. He misses his late mother and is eager for maternal affection, readily engaging with new women introduced into his father's life. He likes to journal to remember things.

Jasper is Oscar's two-year-old son. He tags along with his father and older brother and is quick to seek comfort from adults. He has little to no memory of his late mother.

Ann is Rob's partner. She moved in with Rob when Casey's mother temporarily left the family to pursue an affair in Phoenix, stepping into a fraught domestic situation.