Ronnie is a 17-year-old former piano prodigy forced to spend her summer in Wrightsville Beach. She harbors deep anger over her parents' divorce and blames her father entirely for the fracture in their family. She adopts a hostile exterior with dark clothing and a cynical attitude, refusing to play the instrument that once connected her to her father. Despite her defensiveness, she acts quickly to protect vulnerable creatures and people.

Steve is a former Juilliard professor and concert pianist living in a modest coastal bungalow. He experiences frequent, exhausting stomach problems but keeps his health struggles private to enjoy his summer with his children. He responds to his daughter's severe hostility with gentle patience rather than discipline. He channels his creative energy into building a stained-glass window for the local church.

Will is an athletic and popular local teenager whose wealthy background contrasts with his grounded work ethic. He balances his time between his family's auto shop and volunteering at the local aquarium. He carries a heavy burden of guilt regarding a recent incident in the community. He immediately recognizes the genuine kindness beneath Ronnie's tough exterior.

Marcus is a dangerous local youth who uses physical intimidation to exert control over his social circle. He holds a deep resentment for wealthy residents and finds amusement in causing chaos. He manipulates his girlfriend and immediately views Ronnie as an appealing new target for his aggression. He maintains a disturbing fascination with fire.

Jonah is Ronnie's 10-year-old brother. He provides a stark contrast to his sister's anger by openly expressing excitement about spending the summer with their father. He eagerly volunteers to assist with the stained-glass window project to maximize their bonding time. His innocent questions frequently cut through the family's unspoken tensions.

Blaze is an unhoused local teenager who bonds with Ronnie over their shared rebellious aesthetics. She projects a tough image but lives in a highly vulnerable situation. She relies entirely on her aggressive boyfriend for survival, which forces her into difficult moral compromises. She introduces Ronnie to the dangerous elements of Wrightsville Beach.

Scott is an athletically ambitious teenager focused heavily on securing a volleyball scholarship. He avoids taking responsibility for his reckless behavior. He perfectly willingly lets others carry the moral weight of their shared mistakes to protect his own future.

Kim is Ronnie and Jonah's mother. She orchestrates the summer trip to Wrightsville Beach hoping the change of scenery will correct Ronnie's recent delinquent behavior. She maintains a practical, exhausted demeanor regarding her daughter's ongoing rebellion.

Ashley is Will's recent ex-girlfriend and a prominent member of Wrightsville Beach's affluent teenage social set. She deeply resents Will's interest in the new girl in town. She actively attempts to undermine their developing connection through gossip and direct confrontation.

Pastor Harris leads the local congregation whose church building recently burned down. He suffered injuries during the blaze but remains a spiritual anchor for the community. He serves as a longtime friend and confidant to Steve.

Pete is a local police officer who monitors the town's youth population. He personally intervenes when Ronnie stays out late with a dangerous crowd, bringing her safely back to her father's house.

Susan is Will's mother. She maintains rigid standards regarding formality and social class within her massive Georgian mansion. She immediately disapproves of her son's new relationship, viewing the newcomer as entirely unsuitable for their family's elevated status.

Tom is Will's father. He runs a successful auto shop and maintains a much more approachable demeanor than his wife. He actively attempts to make visitors feel comfortable despite the glaring class differences between their families.

Megan is Will's older sister. Her upcoming wedding serves as a major social event in Wrightsville Beach. The extravagant preparation for her marriage highlights the vast financial disparity between her family and the Millers.

Teddy runs with the local delinquent crowd. He follows Marcus's orders without question and participates in the group's intimidation tactics along the beach.

Lance is another member of the destructive local friend group. He provides numerical support when the group's leader decides to corner or intimidate other teenagers.