Inés is the Mother Superior of a convent in the mid-19th century. With a stern demeanor and a strict adherence to routine, Inés looks down upon the peasants of the area, considering them uncivilized. During mass, a dirty and toothless peasant woman named Jacinta enters the chapel with incense, filling the space with smoke. Inés feels unwell, collapses to the ground, and experiences a mystical vision. The following day, Inés awakens convinced that she has had a divine encounter. The Bishop, representing a new era of the Church, believes that the Mother Superior is unwell, while the nuns suspect she is possessed. Despite the efforts of the sisters and the Bishop, Inés's visions become more intense, and her behavior grows increasingly strange and unhealthy; her body becomes covered in ulcers. One night, the nuns pour boiling water on Inés in an attempt to purify her. This event triggers her most profound ecstasy episode, during which, guided by Jacinta, she experiences the deepest connection with the divine.