Sara is a thirty-one-year-old woman living on a modest, isolated homestead in West Hall, Vermont, during the early twentieth century. She grew up in poverty, which taught her practical survival skills like shooting and skinning animals. Following multiple pregnancy losses and the death of her infant son, she focuses all her affection and attention on her surviving daughter, Gertie. She maintains a deep fascination with the supernatural concepts introduced to her during childhood.

Martin is Sara's husband. He grew up as a quiet, bookish boy who lived in the shadow of his more assertive brother. An encounter in the woods left him with a permanent foot injury and a limp. He attempts to maintain the farm's daily routines while harboring deep concerns about his wife's mental health and her unusually intense attachment to their daughter.

Gertie is Sara and Martin's ten-year-old daughter. She possesses a highly active imagination and claims to communicate with unseen entities she calls "the winter people." She frequently seeks out secret hiding places within the farmhouse walls and closets. Her sudden disappearance during a severe winter snowstorm serves as the catalyst for her parents' desperation.

Auntie is a half-Quebecois, half-Indigenous woman who took over raising Sara and her siblings after the death of Sara's mother. She practices natural healing methods and understands local folklore, which causes the townspeople to view her with suspicion and label her a witch. She provides young Sara with instructions on how to summon the dead, sealed in an envelope for future use.

Katherine is an artist who recently relocated to Vermont from Boston following the consecutive deaths of her young son and her husband. She channels her overwhelming grief into building intricate miniature dioramas. She moves to West Hall specifically to trace her late husband's final steps, hoping to understand why he visited the rural town just before his fatal car accident.

Ruthie is a nineteen-year-old woman living on a self-sufficient, off-the-grid homestead in present-day West Hall. She longs to leave her rural life to attend college but feels trapped by her family's limited finances. When she wakes up to find her mother missing without explanation, Ruthie must immediately step up to care for her younger sister while investigating the disappearance.

Alice is Ruthie and Fawn's mother. She manages a large garden and raises chickens on their isolated Vermont property. She strictly prohibits modern technology like cell phones and computers in their home. Her sudden, unexplained disappearance leaves her daughters vulnerable and forces them to uncover hidden secrets within the farmhouse.

Fawn is Ruthie's ten-year-old sister. She is a quiet, solitary child who frequently plays hide-and-seek and holds whispered conversations with her doll, Mimi. Her habits and mannerisms closely parallel those of Gertie Shea, who lived in the same house a century earlier.

James is the deceased father of Ruthie and Fawn. He was a highly educated man who met Alice at Columbia University before abandoning city life for an idealistic homesteader existence in Vermont. He died of a presumed heart attack in the woods near the property two years prior to the current events.

Gary is Katherine's late husband, a professional photographer who died in a car crash. Prior to his death, he purchased a box of old photographs at an antique shop, which contained mysterious instructions and an engraved bone ring. His subsequent secretive behavior and fatal trip to West Hall drive the present-day mystery.

Austin is Katherine and Gary's young son. He passed away from leukemia at the age of six, roughly two years before the main events of the present-day timeline. His death fractured his parents' lives and serves as the emotional core of their actions.

Buzz is Ruthie's teenage boyfriend who works at a local scrap-metal yard. He holds a strong interest in UFOs, conspiracy theories, and unexplained phenomena. He frequently assists Ruthie in her attempts to uncover the truth behind her mother's disappearance, providing both transportation and a skeptical perspective.

Lucius is Martin's brother and the local doctor in West Hall during the early twentieth century. He is described as stronger, faster, and more confident than Martin. He takes a strictly medical and practical view of Sara's intense grief, frequently diagnosing her behavior as "acute melancholia" and recommending sedatives.

Amelia is Sara's niece. She takes an active interest in the regional spiritualist movement, frequently visiting mediums in Montpelier. She attempts to draw Sara out of her deep depression by introducing her to table-rapping sessions, hoping to provide her grieving aunt with closure.

Candace is a woman living in Connecticut who becomes entangled in the present-day mystery. She lost custody of her son, Luke, to her ex-husband and behaves erratically. Desperate for money to hire a lawyer, she travels to Vermont believing the Washburne family possesses valuable antique documents belonging to her missing relatives.

Thomas is Candace's brother. He and his wife Bridget vanished sixteen years before the main events of the present timeline. Their wallets are discovered stashed beneath a rug in the Washburne farmhouse, prompting Ruthie to investigate their identities.

Bridget is Thomas's wife, who disappeared alongside him years ago. Ruthie shockingly recognizes Bridget's face from a recurring dream about a bakery, a realization that severely unnerves her.

Lou Lou runs a local café in the town of West Hall. She serves as a source of information for Katherine, providing details about Gary's activities and his meeting with an older woman just before his fatal accident.

Mrs. Willard is a medium operating out of Montpelier. She conducts table-rapping sessions and claims the ability to channel spirits, successfully relaying a highly specific message that shakes Sara's skepticism.

Hester is a young girl who died of typhoid fever. She is the very first "sleeper" that young Sara witnesses wandering through the Vermont wilderness, an experience that permanently validates Auntie's supernatural teachings in Sara's mind.

Cora is Hester's mother. Following her daughter's death from typhoid fever, she intercepts Sara in the woods and demands absolute secrecy regarding what the young girl has just witnessed among the trees.