Isa is a civil service lawyer living in London with her partner and their six-month-old infant. She relies on a carefully constructed facade of normalcy to suppress memories of her time at Salten House and the secrets she shares with her former classmates. Her deep loyalty to her boarding school friends conflicts directly with her present responsibilities, causing immediate friction in her home life. The stress of maintaining past deceptions pushes her into a highly fragile emotional state.

Kate lives alone with her white German Shepherd in the crumbling coastal property where she grew up. She relies on an inherited resilience to endure the isolation caused by her father's absence and the subsequent local gossip. Remaining in Salten traps her physically and emotionally, yet she refuses to abandon her childhood home.

Thea works at a casino in London and carries the physical toll of her coping mechanisms, including anorexia and heavy drinking. Coming from a wealthy but problematic background, she has bounced between various jobs and locations since her expulsion from Salten House. She originally modified the rules of the group's childhood deception game to target figures of authority rather than vulnerable students.

Fatima works as a medical doctor and raises two children with her husband, Ali. Following the birth of her son, she embraced the Muslim faith, adopting a sober and dedicated lifestyle. This religious awakening provides her with a framework for seeking atonement, though she remains fiercely loyal to her teenage peer group.

Luc is a French national who lived intermittently at Tide Mill during his youth following severe abuse in his home country. He views the returning women with intense anger, holding them responsible for his subsequent exile. His volatile adult demeanor contrasts sharply with the gentle teenager the girls remember.

Ambrose is a recovering heroin addict who secured a teaching position to keep his daughter enrolled at an elite institution. He eschews traditional discipline, encouraging his students to call him by his first name and permitting relaxed behavior in his studio. His disappearance seventeen years prior serves as the central inciting incident for the returning women.

Mary serves as a central figure in the local village community, representing the working-class locals who resent the wealthy boarding school students. She maintained a close friendship with Ambrose Atagon but strongly disapproves of his daughter and her social circle. She actively perpetuates negative rumors regarding the former students.

Owen works for the Home Office and provides a stable, predictable foundation for his family. He cares deeply for his infant daughter but feels actively excluded from participating in her daily care. His partner's sudden departure and evasive answers cause him to reasonably suspect infidelity.

Mark serves as a police officer in the local community and is the son of the post office clerk. During his youth, he suffered from severe acne and became the target of a malicious rumor spread by the boarding school girls.

Miss Weatherby acts as the housemistress at Salten House, enforcing the institution's rigid disciplinary standards. She actively attempts to integrate isolated students into the broader school community, though her efforts are largely rejected.

Freya is a six-month-old infant whose daily care dominates her mother's routine. Her presence introduces a new layer of vulnerability to her parents' lives, demanding constant attention and protection in unfamiliar environments.

Shadow is a white German Shepherd who lives at Tide Mill. The dog provides companionship and security in the isolated, crumbling home.

Ali works as a medical doctor and resides in London with his family. He supports his wife's career and shares her religious devotion.

Mireille is a French national who struggled with addiction and proved unable to care for her child. Her chaotic lifestyle exposed her son to severe abuse before she relinquished his care.