Agnes is a fiercely independent young woman who grows up near the forest and later becomes known throughout Stratford for her exceptional healing abilities. She possesses a unique connection to the natural world, keeping a kestrel and maintaining a garden of medicinal plants. As a mother, she is deeply devoted to protecting her children, relying on her herbal remedies and instincts to survive in a society that often views her gifts with suspicion.

The eldest son of a disgraced glove-maker, he feels stifled by his aggressive father and the rigid confines of Stratford. He works as a tutor to pay off family debts but possesses a restless, melancholic spirit and a sharp intellect. His chance meeting with Agnes provides an initial escape, though he harbors intense creative ambitions that pull his attention toward the playhouses of London.

Hamnet is an eleven-year-old boy who shares a profound, almost inseparable bond with his twin sister, Judith. He is highly intelligent and prone to daydreaming, frequently slipping away from his physical surroundings into his own imagination. When Judith falls ill with a sudden sickness, Hamnet takes it upon himself to find help, demonstrating absolute loyalty and protectiveness toward her.

Judith is Hamnet's twin sister, a delicate girl who was born frail and has always required extra care. She is heavily dependent on her twin brother's company and finds comfort in collecting and nurturing stray cats. Her sudden, severe illness sets the primary events of the story in motion.

Susanna is the eldest child of Agnes and her husband. At nearly fourteen years old, she carries the burden of practical responsibilities in the household and often resents her parents' eccentricities. She longs for a conventional life, standing in sharp contrast to her dreamy brother and fragile sister.

Joan is the second wife of Agnes's father and steps in to run the farm at Hewlands after he dies. She is a hard-working, highly conventional woman who fears Agnes's unusual abilities and resents the lingering influence of Agnes's deceased mother. She frequently attempts to assign Agnes the worst chores to assert her authority.

Bartholomew is Agnes's fiercely protective older brother and the rightful heir to the Hewlands farm. He is a physically massive man with a gentle disposition toward his sister, often using his intimidating size to ensure others treat her with respect.

John is a glove-maker and the former patriarch of a highly respected Stratford family. He suffered a steep fall from grace due to illegal dealings in the wool trade, leaving him bitter, volatile, and prone to heavy daytime drinking. He maintains a harsh, authoritarian grip on his household and frequently clashes with his eldest son.

Mary is John's wife and the stern matriarch of the Henley Street household. Having birthed eight children and lost three of them to illness, she is fiercely protective of her family but expresses this through strict discipline and rigid control over household matters.

Eliza is the younger sister of the Latin tutor. Unusually for a woman of her time, her brother taught her to read and write. She serves as his confidante during his youth and later forms a warm, supportive relationship with Agnes.

A young, sandy-haired cabin boy from the Isle of Man who travels the world on merchant ships. He is deeply affectionate toward animals, collecting stray cats on board, and unwittingly plays a crucial role in the long chain of events that brings sickness to Stratford.

Rowan is Agnes's deceased biological mother. Raised in the forest, she passed down her unusual affinity for nature and mystical intuition to her daughter. Her memory continues to guide Agnes through difficult moments.

Richard was a wealthy yeoman farmer and the father of Agnes and Bartholomew. He fell in love with a forest-dwelling woman but later married the highly conventional Joan after his first wife's death.

The local medical practitioner in Stratford who dresses in a hideous featureless mask to protect himself from disease. He heavily relies on traditional, often ineffective cures and views Agnes as a bitter rival who steals his patients.

A local Stratford woman who assists in deliveries. She possesses her own intuitive knowledge, correctly sensing that Agnes is carrying twins when others do not.