Hazel is a dedicated rare bookseller transitioning to a new position at Sotheby’s auction house. Evacuated from London to the Oxfordshire countryside as a teenager during World War II, she remains haunted by the unexplained disappearance of her younger sister. Her discovery of a fairy tale book detailing the secret imaginary world she created for her sister sparks an obsessive quest to uncover the truth.

Introduced early on as Hazel’s six-year-old sister, Flora is an imaginative and adaptable evacuee who deeply engages with the fictional world of Whisperwood. Dorothy Bellamy is a persistent Vanity Fair journalist in 1960 who passionately writes a series of articles about lost evacuated children. The narrative follows both the imaginative young girl navigating wartime displacement and the persistent writer determined to uncover the stories of displaced children.

Harry is a thoughtful and artistically inclined boy who lives in the rural village of Binsey with his mother. He quickly befriends Hazel and her sister, helping them adjust to their new environment and defending them from local bullies. As he grows older, he transitions from a mathematically minded student to an artist living in a colony in St. Ives.

Barnaby is a wealthy and practical man who connects with Hazel over their shared love of literature and Virginia Woolf. Coming from a privileged background, he tries to be a supportive partner to Hazel in 1960, though his pragmatic nature often clashes with her emotionally driven decisions. He struggles to understand the depth of her obsession with her missing sister.

Bridie is a kind, independent, and warm-hearted woman living in the rural village of Binsey. She offers Hazel and Flora a safe haven away from the terrors of wartime London. Her open-minded, nonconformist approach to spirituality and religion sets her apart from her more conservative neighbors.

Peggy is an American author who recently published the fairy tale book that catches Hazel's attention. She is initially defensive of her work when contacted by a stranger from England, viewing her story as a personal creation passed down from her mother. She grapples with her newfound professional success and her overbearing mother's expectations.

Kelty is Hazel's closest friend in London and a former fellow evacuee. During the war, she was placed with a cruel host and ultimately ran away back to the city. In adulthood, she remains fiercely loyal to Hazel, offering practical support and encouragement during the search for answers.

Imogene is one of four nurses living near the Aberdeen cottage during the war. She holds conservative religious views that clash with Bridie's open-minded spirituality. She occasionally babysits the local children and harbors deep trauma from the horrors she witnessed in the hospitals.

Aiden is the police inspector in charge of overseeing the community and handling official disputes during the evacuation. He remains involved with the Linden family for decades, communicating with Hazel regarding updates on the historical disappearance case.

Mrs. Marchman is a harsh and unwelcoming woman in Binsey who legally volunteers for billeting during the evacuation. She treats her evacuee ward poorly, representing the negative experiences many displaced children faced in the countryside.

Wren is Peggy’s childhood friend and long-standing romantic interest. He encourages Peggy to embrace adventure and investigate the strange phone call from England, despite her mother's vocal disapproval of his past mistakes.

Hazel's mother is a widow who makes the difficult decision to send her daughters to the countryside during the blitz. In 1960, she is remarried to a man named Alastair and carries heavy, unspoken guilt over the past, though she tries to reconnect with her surviving daughter.

Peggy's mother is an overprotective woman who shared the Whisperwood story with her daughter after a family tragedy. She is deeply suspicious of outsiders and actively discourages Peggy's connection with Wren due to his past.

Edwin is the owner of the antiquarian bookshop in London where Hazel works. He is a supportive employer who values Hazel's expertise, though his trust is tested when a valuable book disappears from his inventory.

Tim is the son of the rare bookshop's owner. He works alongside Hazel, offering good-natured envy regarding her upcoming career advancement at Sotheby's.

Poppy is a young woman who was offered a job at the bookshop when she was without a home. She is friendly with Hazel but briefly falls under suspicion when a valuable item disappears from the store.

Tenny is Hazel's younger half-brother from her mother's second marriage. In 1960, he is the same age Hazel was when she was evacuated, serving as a visual reminder of the time that has passed.

Ethan is a childhood friend of Harry's who initially participates in harassing the evacuee children. In adulthood, he has matured into a friendly artist working alongside Harry in the St. Ives colony.

Iris is Imogene's daughter who lives with her mother near Binsey. Because of her floral name, Hazel briefly suspects she might have a connection to the missing child during her investigation.

Lord Dickinson is Hazel's prospective new employer at Sotheby's auction house. He represents her ascending career trajectory, though he reconsiders her job offer after hearing concerning rumors.

Midge is Kelty's young daughter in the 1960 timeline. She accompanies her mother on visits to Hazel and represents the new generation growing up in peacetime.

Alastair is the second husband of Hazel's mother. He provides her with a new life and family dynamic in the years following the war.