In the isolated, rain-lashed village of Thornwood, a place where the soil is as bitter as the hearts of its inhabitants, a mysterious blight known as the "Withering" begins to corrupt the local flora, turning the prized hellebore flowers into sickly, blackened husks. When reclusive botanist Anya Taylor-Joy arrives to study the phenomenon, she discovers the blight is not a natural disease but a parasitic curse tied to a century-old pact made by the village's founding families. As the Withering spreads to the townspeople, manifesting as a creeping decay of the soul, the botanist must team up with a skeptical local historian, played by Paul Mescal, to unearth the dark ritual that binds the community to its poisoned land. Their investigation pits them against a council of elders who guard the secret, forcing the duo to confront a chilling choice: break the curse by exposing a devastating truth, or let the village and its inhabitants slowly rot from within. This gothic folk horror film weaves a tense atmosphere of dread and decay, exploring themes of generational guilt and the poisonous legacy of secrets buried deep in the earth.