Chelsey is a dedicated detective at the Coldwell Beach police department who specializes in missing persons cases. A Japanese American woman adopted by a white family, she frequently encounters casual racism and sexism in her hometown and workplace. She uses her obsessive focus on work to cope with the trauma of her sister Lydia's disappearance and presumed murder.

Ellie is a 19-year-old woman attempting to reacclimate to society and her family after a traumatic, two-year disappearance. She exhibits acute anxiety, dissociation, and a fear of physical touch. She struggles to articulate what happened to her and feels disconnected from her old life and the person she used to be.

Lydia is Chelsey's older sister who went missing when she was 15 years old. The police eventually concluded that she was murdered by a high school senior named Oscar. Her disappearance and presumed death deeply shaped Chelsey's life and her choice to become a police officer.

West is the son of Sergeant Abbott and Governor Regina Pike. He holds deep resentment regarding his parents' divorce and directs much of his anger toward his mother. He owns a business entity that includes a farm co-op and a kennel in the Olympic National Forest.

Noah is Chelsey's husband. He attempts to be supportive but grows increasingly frustrated by Chelsey's inability to separate her work life from their personal life together. He hopes to build a healthy future with his wife, though her fixation on her unresolved childhood trauma strains their marriage.

Sergeant Abbott is Chelsey's boss at the Coldwell Beach police department. He struggles with alcohol use following his divorce from his ex-wife, Governor Regina Pike. He assigns cases to his detectives but often appears eager to close them quickly or pass them to other agencies.

Doug is a detective at the Coldwell Beach police department and the son of Sergeant Abbott. Chelsey remembers him making racist jokes during her childhood. He works alongside Chelsey in the department and investigates the initial scene of Ellie's reappearance.

Jimmy is Ellie's father. During the two years of Ellie's disappearance, he routinely visited the police precinct to check for updates, refusing to give up hope. He is desperate to reconnect with his daughter and bring her out on his boat to help her heal.

Kat is Ellie's mother. She staunchly defended Ellie's character when she first went missing, understanding that the media heavily prioritizes finding girls perceived as perfectly behaved. She breaks into tears upon seeing her daughter's condition and struggles to understand the traumatized woman who returns home.

Sam is Ellie's older sister. She has a wife, Valerie, and a daughter, Mia. She visits the family home to reconnect with Ellie after her return, attempting to gently rebuild their relationship despite their past teenage squabbles.

Danny is Ellie's high school boyfriend. He attempts to visit Ellie after she returns home, bringing his record player to comfort her without forcing her to speak. He remains a loyal presence, willing to help both Ellie and the police when he suspects Ellie is in danger.

Dr. Fischer is a therapist who treats Ellie following her return. She specializes in trauma, explaining how the mind forms a protective maze to cope with horrific events. She employs art therapy and mental exercises to help Ellie process her severe anxiety and dissociation.

Gabrielle is a teenager who went missing five years earlier. Her body was found over two years after her disappearance, leaving her family devastated. Her old University of Washington sweatshirt becomes a crucial piece of evidence in Ellie's case.

Althea is Gabrielle's grandmother, who adopted her grandchildren after their mother lost custody. She experiences immense grief following Gabrielle's disappearance and murder, which contributed to the dissolution of her marriage. She prefers not to know further details about the case to avoid reliving the trauma.

Hannah is a young woman whose missing persons case Chelsey links to the broader investigation. Chelsey desperately wants to find her, bringing her photograph to Ellie in hopes of jogging her memory or securing her cooperation.

Willa is a young girl who went missing at seven years old. She is the daughter of Lewis Salt. Finding Willa becomes a powerful driving force for Chelsey's investigation after discovering the DNA evidence connecting her to Ellie.

Regina Pike is the state governor and the ex-wife of Sergeant Abbott. Her successful political career creates friction with her ex-husband, and their divorce causes lasting resentment within her former family.

Oscar is a high school senior whom Lydia sneaks out to see. He is later found dead, and the local police conclude that he murdered Lydia before dying by suicide.

Lewis is the son of an inmate whose DNA partially matches the blood found on the clothes Ellie returns in. He is initially a lead suspect until Chelsey learns about the disappearance of his daughter, Willa.

Valerie is Sam's wife and the mother of their daughter, Mia. She accompanies Sam to visit Ellie after her return.

Mia is the young daughter of Sam and Valerie.