Maud is an elderly former switchboard operator living with worsening dementia. She relies on a system of handwritten notes scattered around her house to retain information, though her deteriorating condition makes it increasingly difficult to interpret her own clues. Driven by fierce independence, she investigates the current disappearance of her best friend, Elizabeth, while simultaneously reliving vivid memories of her older sister Sukey, who went missing seventy years earlier.

Helen is Maud's daughter, a woman in her fifties who works as a professional gardener. As Maud's primary caregiver, she handles the daily crises caused by her mother's condition, ranging from removing stovetop knobs to retrieving Maud from the police station. The immense responsibility exhausts her, leading to moments of sharp frustration, yet she remains deeply protective of her mother.

Sukey is Maud's glamorous older sister who vanished mysteriously in the period following World War II. She favors fashionable clothing and specific accessories, notably Victory Red lipstick and Evening in Paris perfume. Despite her outgoing nature, she harbors distinct fears about objects in her own home, particularly a glass dome containing stuffed birds.

Frank is Sukey's husband, a handsome man who runs a moving business but actively participates in post-war black-market activities. He uses his connections to provide favors for his neighbors, masking a heavy drinking habit and a highly volatile temper. Young Maud finds his behavior intimidating yet feels oddly drawn to him after Sukey disappears.

Douglas is a milkman who becomes a lodger in Maud's childhood home. He enjoys using American slang and playing records on his gramophone. He pays unusually close attention to Sukey, remembering specific details like the exact shade of her lipstick, which raises young Maud's suspicions about his true intentions.

Elizabeth is Maud's best friend, whom she originally met while volunteering at a local charity shop. She suffers from poor eyesight, rarely ventures outdoors, and fills her house with secondhand pottery and collectibles. Her sudden, unexplained absence from her home drives Maud's frantic search for answers in the present day.

Carla is a paid caregiver hired by Helen to check in on Maud. She frequently discusses alarming news stories regarding crimes against older people, upsetting her client. Carla attempts to enforce daily rules about eating schedules and staying indoors, instructions that Maud routinely bypasses as soon as Carla leaves.

Katy is Helen's teenage daughter. Unlike many adults in Maud's life, she treats her grandmother with a lighthearted kindness, teasing her in a way that makes Maud feel respected and human. She patiently assists Maud during moments of public confusion and memory loss.

Tom is Maud's son who lives in Germany and visits his family only once a year. His physical distance from the situation breeds resentment from Helen, who handles all the daily challenges of their mother's declining health.

Peter is Elizabeth's son. He exhibits little patience for Maud's distressed phone calls and actively removes items from his mother's cluttered house. He responds defensively and with hostility when questioned about his mother's whereabouts.

Maud and Sukey's mother manages the household during the rationing years following World War II. She refuses to believe the worst about her son-in-law Frank after Sukey vanishes, relying heavily on the extra supplies he provides to get the family by.

A strict postman and the father of Maud and Sukey. He harbors a deep distrust of Frank, openly declaring that his daughter should never have married him. He takes an active role in questioning neighbors when Sukey disappears.

Peggy works at the local charity shop where Maud and Elizabeth previously volunteered. She speaks bluntly to Maud, treating her confusion as a burden and publicly reminding her that she is no longer welcome to work there.

Nancy is a woman young Maud meets at the Station Hotel. Frank asks her to sign the hotel register using Sukey's name, a favor she performs without asking questions because Frank intimidates her.