In 1630s New England, a devout Puritan minister, William, leads his wife, Katherine, and their five children—Thomasin (16), Caleb (10), twins Mercy and Jonas (3), and baby Samuel—to the edge of a dark forest. Exiled from their larger plantation for religious reasons, they build a home on the colonial frontier, hoping for a pious new life.
Tragedy strikes when baby Samuel disappears near the woods under mysterious circumstances. Silence ensues, grief settles like a shadow, and the family begins to fracture under intense sorrow. Thomasin overhears her parents debating her culpability, which plants seeds of mistrust.
Thomasin’s older brother Caleb wanders into the woods, encountering a strangely attractive young woman who leads him to a clearing with an ominous goat named Black Philip. The girl seduces him before vanishing, which triggers Caleb's sudden insanity. The family believes witchcraft is afoot and starts searching for supernatural culprits.
The goat, Black Philip—owned by the family—becomes a focal point. Caleb starts erratic behavior around it; the rest of the family suspects the goat might be possessed or a conduit for evil. Ultimately, Caleb dies in a mysterious accident, and Black Philip is banished to the forest. The grief-stricken family grows more divided.
Katherine publicly accuses Thomasin of causing Samuel’s death and Caleb’s disappearances, fanning the flames of paranoia. She’s convinced her daughter is in league with the Devil. Thomasin is locked in a room, isolated and fearful, desperate to stop the spiral of madness.
Twins Mercy and Jonas, underling whispers of evil from the forest, suddenly vanish as well. Katherine, broken by the losses and believing she’s doomed, attempts to kill Thomasin, accused of being a witch. Thomasin defends herself, killing her mother in panic and horror just as Jonas and Mercy return, chanting in an eerily baseless litany.
With nearly everyone dead, Thomasin confronts the truth: the forest has swallowed her family one by one. She’s skinning Black Philip—now revealed as a guardian of witchcraft. When confronted by possessed twins whispering for her to join their coven, she hesitates but ultimately signs a book offered by a figure in the woods.
Thomasin sheds her Puritan identity. She disrobes, untamed, and flies, levitating into the night sky alongside witches, as the woods celebrate. Her transformation is complete: the wronged, isolated girl has become the figure of pure rebellion, beckoning an otherworldly freedom.
