Julia is a dedicated detective chief inspector with the Portishead police. She is known for her relentlessness and attention to detail, treating her job as an intrinsic part of her identity. She faces heavy tension between her intense professional commitments and her family life, particularly following a traumatic incident involving her teenage daughter.

Lewis is a father struggling with profound grief and a desperate need for justice after his daughter disappeared a year ago. Possessing a wired, charismatic energy, he works at a passport center and is relentlessly focused on holding those he believes responsible accountable for his family's tragedy.

Emma is a single mother burdened by protective instincts and internal doubts. Having raised her son alone, she constantly questions her own abilities as a parent. When her son falls under intense public scrutiny, she uproots their lives to protect him, though she remains plagued by quiet suspicions and a desperate need for the truth.

Genevieve is Julia and Art's fifteen-year-old daughter. She is a confident teenager who develops an intense obsession with her mother's police work and true crime. Her new interests stem from lingering trauma and complex feelings following a dangerous encounter with a local mugger.

Matthew is a young man living quietly with his mother. He faces immense public scrutiny and police investigation following the disappearance of his girlfriend a year prior. Steadfast and tight-lipped, he changed his name and moved across town to escape relentless press and harassment.

Jonathan is a detective with the Portishead police and a new father. He is highly detail-oriented, emotionally invested in his work, and specializes in understanding how young people interact online. As Julia's right-hand man, he provides her with crucial support during complex investigations.

Art is Julia's separated husband. Though he currently sleeps in the spare bedroom of their shared home on Sugar Loaf Beach following a marital transgression, he remains a calming, nonjudgmental presence in Julia's life. He historically serves as the keeper of her worries, balancing the immense stress of her police work.

Sadie is Lewis and Yolanda's daughter. She disappeared a year prior to the current investigation, leaving behind unanswered questions that continue to haunt her family and the detectives assigned to her case.

Olivia is a twenty-two-year-old woman whose sudden disappearance triggers a major police investigation in Portishead. Her digital footprint, including recent social media posts about a new house, an upcoming job interview, and a potential boyfriend, forms the center of the investigative team's early efforts.

Price is a long-time police informant who has known Julia for nearly twenty years. He maintains an uncharacteristic loyalty to her and frequently provides the investigative team with crucial street-level intelligence.

Zac is a familiar petty criminal in Portishead. His physical altercation with Genevieve during a mugging attempt sets off a chain of traumatic and highly consequential events for the Day family.

Yolanda is Lewis's level-headed wife. She attempts to balance her husband's intense energy with quiet pragmatism, trying to move forward and establish new traditions in the wake of their family tragedy.

Erin is the head of the forensics unit for the Portishead police. She is a sharp, observant colleague who notices small discrepancies in protocol and behavior, making her a valuable asset to investigations.

Robert is a detective constable with the Portishead police. He assists Julia in conducting interviews, gathering evidence, and escorting persons of interest throughout the department's investigations.

Annie is one of Olivia Johnson's prospective roommates. She provides early text message correspondence to the police, helping establish the timeline of Olivia's brief move-in before her disappearance.

Patricia is the prosecutor assigned to handle the legal charges against suspects apprehended by the Portishead police team. She evaluates the strength of evidence before moving cases forward to trial.