Hermine is the fiercely independent matriarch of the Zook family who provides natural remedies to the people of Whiteheart. She isolates herself on a swampy island, distrusting men and forbidding them from crossing her bridge. She acts as a strict guardian to the women in her family while maintaining an almost mystical connection to the local flora and fauna.

Dorothy is an eleven-year-old girl raised on an isolated island by her grandmother. She loves the natural world and refuses to eat meat. Finding comfort in the predictability of mathematics, she studies diligently from textbooks sent by her aunt. She operates as a caretaker for the island's animals and eagerly awaits her mother's sporadic visits.

Rose Thorn is the beautiful, restless youngest daughter of the Zook family. Known for her independent spirit and reluctance to engage in strenuous farm labor, she frequently travels between Whiteheart and California. Her presence brings a lively energy to the community. However, she struggles heavily with the expectations of those who love her and carries deep personal burdens.

Titus is an industrious farmer in Whiteheart who suffers from hemophilia. He deeply values his agricultural legacy, consistently planting his fields earlier than anyone else in town. His persistent affection for Rose Thorn conflicts directly with her desire for freedom, putting him at odds with the traditional family life he envisions.

Maryrose is Hermine's middle daughter who pursues formal medical training. She values sterile environments and practical solutions over the unpredictable conditions of the swamp. Her assertive nature often causes friction with her relatives, though she genuinely works to ensure their physical and financial well-being.

Primrose is the eldest of the Zook daughters, working as a successful attorney far from the Whiteheart swamp. She maintains a moderating presence within the family dynamics, balancing out the extreme personalities of her sisters. She regularly sends math books to Dorothy, providing the young girl with intellectual stimulation.

Wild Will is Hermine's banished former husband. Decades ago, he constructed the wooden bridge connecting the island to Boneset. Following a serious transgression, Hermine permanently exiled him from the property, establishing her strict rule against men crossing the swampy threshold.

Reverend Roy is the local spiritual leader who openly opposes Hermine's healing practices. He views her methods as inherently sinful and commands his congregation to rely on prayer instead. Despite his strict religious mandates, he maintains a personal connection to the Zook family.

Whitby is a local Whiteheart resident who spends time gathering with other men at the tavern. He carries a heavy burden regarding Rose Thorn, struggling quietly with his failure to intervene during a violent event in the past.

Standish is a local man who harbors deep resentment toward Hermine's influence over the women in his family. He lurks near the island, watching the Zook property with malicious intent and representing the broader community's underlying tension with the matriarch.

Lorena is a local woman who enters a relationship with Titus. She represents a stable, traditional alternative to the unpredictable nature of Rose Thorn, offering Titus the conventional family life he desires on his farm.

Baba Rose is Hermine's deceased grandmother and the original matriarchal healer of the Zook line. Though she passed away years ago, her legacy heavily influences Hermine's strict adherence to traditional remedies and her ritualistic lifestyle.

The Massasauga is a venomous rattlesnake native to the swampy region surrounding the island. Captured by Hermine for its medicinal venom, the snake becomes a source of tension when Dorothy's interference alters its containment.

Ozma is a dog gifted to the Zook family who becomes Dorothy's loyal companion. Named after a literary character, the dog remains closely tied to the daily rhythms of Rose Cottage.

Aster is a donkey kept on Massasauga Island. When infant Dorothy refuses all other forms of nourishment, Hermine utilizes Aster to provide the specific milk the child needs to survive.