Caroline is a 28-year-old aspiring writer who recently quit her New York publishing job. Seeking distance from her famous author mother, she accepts an 18-month writing fellowship in the coastal town of Greenhead, Massachusetts. She finds herself drawn to the local environment and the unpretentious men she meets, but her status as an outsider complicates her life in the tight-knit community.

Bailey is a wealthy, independent 34-year-old woman who lives alone in her parents' ostentatious former home, which she calls "Budweiser Manor." She maintains two pet swans and values her personal freedom above all else. She discovers she is pregnant with Van's child following a casual winter encounter, an event that forces her to consider the realities of single motherhood and her long-standing dynamic with him.

Augusta is a meticulous and image-conscious mother who heavily values the stability of her traditional family life. She acts as the social gatekeeper for her tight-knit circle of friends, viewing newcomers with deep suspicion. Her secure worldview fractures when she discovers a strange pair of blue lace underwear in her living room sofa cushions, sending her into a quiet spiral of anxiety about her husband's fidelity.

Fran is a pragmatic engineer and a fiercely independent anchor for her local friend group. She refuses to merge her finances with her long-term partner, RJ, or accept his casual marriage proposals. She silently carries the mental load for her household while simultaneously managing the fallout of her father's severe sports gambling addiction and her brothers' enabling behavior.

Van is an earnest environmental scientist working for The Trustees of Reservations at the Crane Estate in Greenhead. He monitors nesting sites for piping plovers and feels a deep sense of stewardship for the local land. His budding romance with Caroline hits a severe obstacle when he learns that his high-school flame, Bailey, is pregnant with his child, forcing him to balance his new feelings with his impending fatherhood.

Colin is Augusta's husband and a quiet, steady presence within the Greenhead friend group. He prioritizes stability and order in his domestic life, projecting the image of a committed father and partner. He maintains a close friendship with his brother-in-law, Eben, though unspoken tensions occasionally surface during group activities like pickup basketball games.

RJ is Fran's long-term partner and the father of their two young sons, London and Hale. He embraces a fun-loving, carefree approach to life, participating in local traditions like the Greasy Pole competition dressed as a greenhead fly. His immaturity and reliance on recreational cannabis place the bulk of their household's domestic responsibilities squarely on Fran's shoulders.

Eben is Augusta's older brother and a long-time member of the central friend group. He is building a life with his partner, Max, as they renovate a home together. He maintains a complicated dynamic with his sister, marked by emotional distance, while remaining closely tied to the group through his history with his brother-in-law, Colin.

Ned is a slick New York literary agent who represents the transactional urban environment Caroline wishes to escape. He acts as the agent for Caroline's mother, Gwendolyn, and has professional ties to the Palmer Preston estate that funds Caroline's fellowship. His presence in Greenhead reminds Caroline of the professional betrayals she suffered in the city.

Gwendolyn is Caroline's mother and a massively successful thriller author with ten million readers. She is competitive and status-obsessed, frequently diminishing Caroline's literary achievements in favor of commercial success. Her massive shadow drives her daughter to seek independence in a small coastal town.

Max is Eben's partner. He provides an outsider's perspective on the insular Greenhead friend group, bluntly noting how secretive their dynamics are.

Kon is Fran's brother. He exhibits reckless financial behavior, regularly losing valuable items and large sums of money on sports bets alongside his brother and father.

Damien is one of Fran's brothers. He enables the family's destructive gambling habits and relies on his sister to manage their resulting financial crises.

London is the son of Fran and RJ. He frequently requires his mother's attention during the school day and shows an interest in collecting rare Pokémon cards.

Hale is the young son of Fran and RJ. His fascination with animal behavior occasionally mirrors the primal social dynamics of the adults around him.

Zoey is a local teenager who works as a babysitter for the Nickerson family. Her presence in the house unknowingly intersects with Augusta's private anxieties about her marriage.

Nina is Caroline's friend from outside the Greenhead circle. She provides a sounding board for Caroline's insecurities regarding Van's complicated history.

Juliette is Van's mother. She holds a casual attitude toward her past, noting a brief connection with a famous musician when discussing baby names.

Clara is Bailey and Kylie's mother. She and her husband maintain an ostentatious lifestyle, frequently wintering in Florida and avoiding the colder Massachusetts weather.

Jay is Bailey and Kylie's wealthy father. He pressures his daughter to conform to traditional family structures despite her firm resistance.

Kylie is Bailey's sister. Her pragmatic, almost cynical approach to her marriage contrasts with the romantic anxieties experienced by the rest of the Greenhead group.

Jeff is Kylie's husband. His transactional entry into marriage highlights the varied and unconventional partnerships accepted within Bailey's extended family.

Mac is an old college friend of Bailey's who lives in Los Angeles. He represents an uncomplicated connection to her past, independent of the tight-knit Greenhead circle.