Anna is an 18-year-old widow raising two young sons, Jamie and Tom, in the village of Eyam. She supports her family by keeping sheep and working as a maid for the town's rector following the mining death of her husband, Sam. Despite lacking formal education, she possesses a keen intelligence and learns to read under Elinor Mompellion's tutelage. Her resourcefulness and natural curiosity serve her well as her quiet community faces severe hardship.

Michael is the newly installed Anglican rector of Eyam, having replaced the former Puritan leadership. He approaches his congregation with compassion, striving to unite the villagers regardless of their specific religious leanings. As a powerful speaker, he rides a large stallion named Anteros and commands deep respect from his flock. He faces the daunting task of guiding his community through overwhelming physical and spiritual trials.

Elinor is the educated, high-born wife of the town's rector, Michael Mompellion. Despite her elevated social standing, she treats the villagers with genuine equality and kindness, frequently engaging in the community's daily chores. She takes a special interest in Anna, teaching the young widow how to read and sharing her fascination with the medicinal properties of plants.

Mem serves as Eyam's primary healer and midwife, utilizing a vast knowledge of plant medicine and herbal remedies. Because her methods rely on natural elements rather than the harsh practices of traditional barber-surgeons, the deeply religious villagers view her with a mixture of reliance and suspicion. She possesses a gentle bedside manner and acts as a stabilizing presence during medical emergencies.

Aphra is Josiah Bont's wife and Anna's stepmother. She subscribes heavily to local superstitions and folklore, often prioritizing magic over the religious doctrines preached at the local church. She raises several young children in a crowded household and tolerates her husband's excessive drinking out of sheer practicality.

Anys is Mem Gowdie's niece and works alongside her aunt as a skilled healer in Eyam. She openly rejects traditional societal expectations for women, refusing to marry and proudly maintaining her independence. Her progressive views on personal freedom and medicine frequently anger the conservative elements of the village.

Josiah is Anna's father and Aphra's husband. Carrying severe trauma from his time forced into naval service as a youth, he struggles with alcoholism and is prone to violent outbursts. He frequently exploits his neighbors and treats his family with hostility. His presence acts as a volatile element within Eyam's social structure.

George is a young tailor from London who takes up lodging in Anna Frith's attic. He brings energy and joy to her household, entertaining her young sons with stories of his travels and sewing beautiful garments. His arrival awakens a renewed sense of hope in Anna following her husband's death.

Jamie is Anna's young son. Still recovering from the death of his father in a mining accident, he finds joy in playing in the village and forms a quick attachment to the new boarder, George Viccars.

Tom is Anna's infant son, born shortly around the time of his father's death. He requires constant attention and represents Anna's most vulnerable tie to the world.

Sam is Anna's late husband, a lead miner who died in a tragic cave-in. He was a devoted, simple man who deeply loved his family and protected Anna from her father's abuse.

Elizabeth is the demanding daughter of Eyam's wealthiest family. She expects privilege and deference. She frequently clashes with Anna because she maintains strict views on social hierarchy.

The patriarch of the Bradford family and the highest-ranking social figure in Eyam. He rules his household and servants with an iron fist and places his family's safety above any obligation to the village.

The matriarch of the Bradford family. She lives under the harsh rule of her husband and relies on her daughter Elizabeth for support during a severe personal crisis.

Mr. Stanley is the former Puritan rector of Eyam who resigned his post after refusing to conform to Anglican mandates. Despite his theological differences with Michael Mompellion, he maintains an authoritative presence among the village's religious dissenters.

Alexander is the village tailor who hires George Viccars as an assistant, inadvertently bringing an illness into his home through a shipment of London cloth.

Mary is Alexander's wife. She relies on traditional barber-surgeons over the Gowdies' plant medicine when her household falls ill. Her choices reflect the broader community's distrust of unconventional herbalism.

Jane is a devout young woman who works as a babysitter for Anna's sons. The pressures of the village's isolation eventually push her to abandon her strict Puritan upbringing.

Maggie is the talented, hardworking cook for the Bradford family. When her employers suddenly dismiss their staff, she faces a dangerous journey to find safety.

Brand is a servant for the Bradford family who demonstrates courage and loyalty when he attempts to transport his fellow servant Maggie to safety after they are turned out of their home.

Lib is a friend of Anna's who works in the fields. Their friendship becomes strained as fear and suspicion overtake the village.

Merry is a young Quaker girl whose family holds a valuable mining claim. Left vulnerable by the village's sickness, she requires outside assistance to secure her inheritance.

Faith is Aphra and Josiah Bont's youngest child. She lives in a chaotic and often fearful household overshadowed by her father's drinking and her mother's superstitions.

John is a village farmer who turns to extreme religious practices. He adopts the life of a flagellant, believing physical suffering will appease divine anger.

Urith is John Gordon's wife. She suffers under her husband's sudden and extreme religious zeal, which strips their home of all comforts.

Christopher is a young man in the village who falls severely ill. His vulnerability makes him a target for opportunistic locals.

Anteros is Michael Mompellion's powerful stallion. The large horse elevates the rector's physical presence in the village and later represents freedom and escape.