Sara is a poet and mother living in self-imposed exile in Lubec, Maine. Eight years ago, she survived a sexual assault in Savannah and subsequently fled to protect her resulting daughter from her attacker's powerful family. She is cautious and structures her life entirely around keeping her child safe. A sudden medical emergency forces her to return to Georgia, testing her carefully constructed boundaries.

Jacob is a brilliant astrophysicist who studies the aurora borealis, having traveled the world to distance himself from his family's dark history. He is the identical twin brother of the man who assaulted Sara. Jacob returns to Savannah to rehabilitate a remote island cabin and attempt to process his lingering guilt and anger. He values logic and science but actively works to understand his suppressed emotions.

Daniel is Jacob's identical twin brother, currently serving a prison sentence for the sexual assault of Sara Lancaster. He is highly intelligent but historically arrogant and detached from the emotional damage he causes. Recently diagnosed with cancer, he spends his time in prison leading educational and gardening projects, though his motivations for atonement remain questionable to those he hurt.

Birdie is the matriarch of the Wyler family and a woman of immense intellect, holding degrees in biology and chemistry. She directs her intense focus entirely toward her children, particularly Daniel. During Daniel's trial, she used her wealth and influence to attack Sara's credibility. She remains cold, calculating, and stubbornly in denial about her son's guilt.

Alana is Sara's eight-year-old daughter, a recognized genius with an exceptional talent for mathematics and languages. She is homeschooled and closely guarded by her mother, completely unaware of her paternal lineage. Her intense curiosity and desire to participate in public science competitions challenge her mother's strict rules about remaining hidden.

Hosea is Sara's father and the owner of a newly renovated local bookstore in Savannah. He suffers from a serious, active brain aneurysm, an illness he kept secret from his daughter while he worked to finish his store. He possesses a unique communication style, expressing his thoughts, advice, and affection almost entirely through quoted poetry.

Sylvia is Hosea's long-time girlfriend and a surrogate mother figure to Sara. She oversees a local educational summer camp in Savannah. Sylvia is practical, deeply caring, and unafraid to challenge Sara's tendency to run away from difficult situations, actively pushing her to reintegrate into the Savannah community.

Naomi is the deceased sister of Jacob and Daniel Wyler. She died in a car accident involving a drunk driver at the age of fifteen, a tragedy that permanently fractured the Wyler family. Her memory continues to influence Jacob, who sees strong parallels between her personality and Alana's.

Tom was the wealthy patriarch of the Wyler family and father to Jacob, Daniel, and Naomi. Overwhelmed by grief following Naomi's death and the public shame of Daniel's criminal trial, he died by suicide, leaving his remote island property to Jacob.

Locke is Jacob's friend and a fellow resident of the coastal area around Savannah. He owns a boat and provides practical assistance to Jacob as he works to restore his isolated island property.

Marsha is the long-time housekeeper for the Wyler family. Because Birdie is emotionally distant, Marsha stepped into a maternal role for Jacob during his youth, offering him the warmth and care his biological mother withheld.

Brixton is a child attending the educational summer camp run by Sylvia. He shares a love for logic puzzles and quickly befriends Alana when she visits the camp, helping her feel comfortable in Savannah.