Jenna is a traumatized artist who leaves her life in Bristol to start over in the remote Welsh village of Penfach. She rents a rundown cottage and attempts to establish a quiet routine by taking photographs of messages written on the beach sand. She maintains a highly guarded demeanor and actively avoids drawing attention to herself.

Ian is a university guest lecturer and Jenna's husband. He expects strict adherence to his preferences at home and reacts with intense irritation whenever Jenna displays emotional vulnerability. He evaluates her actions critically and seeks to maintain absolute authority over their domestic life.

Ray is an experienced Detective Inspector leading the Bristol CID team investigating a child's death. He actively uses heavy caseloads as an excuse to avoid dealing with problems at his own home. His intense focus on closing the hit-and-run case revives his professional enthusiasm but heavily strains his marriage.

Kate is a young Detective Constable working under Ray on the hit-and-run investigation. She takes the death of the young victim personally and refuses to let the case grow cold. She often speaks her mind bluntly to superior officers and forms a close professional bond with Ray during their late-night shifts.

Patrick is a gentle veterinarian practicing in the coastal region near Penfach. He volunteers for the local lifeboat station and enjoys a strong reputation among the villagers. He notices Jenna on the beach and patiently attempts to draw her out of her self-imposed isolation.

Mags is a former police officer who left her career to manage her family's household. She handles her children's daily needs and school disciplinary issues entirely on her own. She feels increasingly ignored by her husband and frustrated by his constant physical and emotional absence.

Anya is a young mother living in the Fishponds area of Bristol. She experiences catastrophic grief after a car strikes and kills her five-year-old son in the rain. She faces intense public scrutiny and harsh judgments from strangers regarding the circumstances of the accident.

Jacob is Anya's five-year-old son. A speeding car strikes him on a rainy evening, and his death triggers a massive police investigation in Bristol.

Bethan owns a local shop in the Welsh village of Penfach. She serves as Jenna's primary point of contact in the village, offering her practical advice and encouraging her to turn her beach photography into a source of income.

Iestyn is a local Welsh resident who rents the damp Blaen Cedi cottage to Jenna. He relies on his quad bike to get around and frequently dismisses Jenna's requests to fix her broken front door lock, insisting that crime does not happen in their village.

Jake is a reliable police sergeant at the Bristol CID, often referred to by his colleagues as Stumpy. He steadily works through administrative tasks, processes closed-circuit television footage, and coordinates with other local police stations to gather intelligence for Ray's team.

Olivia is the Chief Constable managing the Bristol police force. She focuses heavily on public relations and department statistics, frequently pressuring Ray to close unsolved cases so the department can appear more effective.

Eve is Jenna's older sister. The two share a strained history due to childhood disagreements regarding their parents, resulting in long periods of total estrangement.

Tom is Ray and Mags's teenage son. He skips classes and exhibits sullen behavior at home, creating deep tension between his parents regarding how to handle his discipline.

Lucy is Ray and Mags's young daughter. She attends school and frequently bickers with her older brother in the mornings.

Beau is a spaniel-mix puppy abandoned in the Welsh countryside. Jenna rescues the dog, and his constant need for care provides her with a reason to establish a daily routine.

Marie is a woman from Ian's past. Ian briefly reflects on his previous relationship with her when evaluating Jenna's behavior early in their romance.