Ava is a bright, magically gifted young woman from Maine who arrives at Radcliffe College seeking freedom. Born with an eleventh finger that was surgically removed, she possesses inherent abilities she was taught to suppress, such as levitation and communicating with crows. As she joins the Lilith Society, she begins to embrace her true nature and investigate her hidden heritage.

Lauren is a cynical, pale-haired student from a prominent Cambridge family of witches. Traumatized by the tragic death of her parents, she explores the left-handed "Crooked Path" of dark magic as a defense mechanism against emotional vulnerability. She is fiercely protective of her friends but prone to destructive and controlling impulses.

Jamie is a handsome, rebellious Harvard student and a direct descendant of the infamous Puritan witch-hunting Mather family. Like Ava, he bears a scar from a removed eleventh finger, a mark of his suppressed magical heritage. He struggles with deep self-loathing and the heavy burden of his family's oppressive expectations.

Lionel is Lauren's older brother and a Harvard medical student who possesses the gift of sight. Empathetic and nurturing, he processes his family trauma by seeking to heal others. As a gay man in the 1950s, he endures the intense societal paranoia of the Lavender Scare, seeking love in secret clubs that risk police raids.

Rose is the historical "first witch of Cambridge," whose life is chronicled in hidden documents from the 1690s. Originally a servant imprisoned in London, she escapes to the American colonies and establishes a safe haven for outcast women. Her story serves as a guiding legacy for the modern Lilith Society.

Paul is Jamie's father and a wealthy, ruthless attorney who fiercely protects the Mather family legacy. He enforces strict conformity, aggressively suppressing any sign of magic or deviation within his household. He views Jamie's rebellious nature and connection to Ava as direct threats to his authority.

Eugene Sharpe is a charismatic professor at Harvard who studies the Anthropology of Magic. He uses his academic authority and knowledge of the "Crooked Path" to manipulate vulnerable female students. His interest in magic is predatory, viewing it as a source of power to be acquired rather than a sacred heritage.

Cotton is a 17th-century Puritan minister and a central figure in the Salem witch trials. Plagued by self-hatred over his own suppressed magical nature, he aggressively persecutes women with the very abilities he despises.

Known locally as "Goliath" due to his imposing height, Carrick is a reclusive, introverted tattoo artist with a gentle nature. He possesses a deep artistic intuition, quickly recognizing Lauren's vulnerability beneath her abrasive exterior.

Maureen is a pragmatic nursing student and a fellow witch who befriends Ava at work. Unlike the academic members of the Lilith Society, her magic is rooted in practical, community-based folk traditions.

Billy is Maureen's half-brother and a detective for the Cambridge police. As a gay man in the 1950s, he lives in constant fear of his career being destroyed by the Lavender Scare, forcing him to hide his true identity.

May is the wife of Harvard President Increase Mather in the 1690s. She harbors a secret magical nature, choosing to suppress her true identity in exchange for safety and social standing within Puritan society.

Increase is a powerful 17th-century Puritan minister and president of Harvard College. While historically known for his role in the witch trials, he is manipulated by rumors into publicly denouncing spectral evidence to protect his wife.

Jeanne is Ava's strict, conservative guardian who raises her in rural isolation. Terrified of the girl's magical nature, she forces Ava to conform, burning her books and punishing any display of supernatural talent.