Lucia and Ana María, two young postulants newly arrived at a small convent, find themselves caught up in the strange events that take place there. Sister Águeda, the Mother Superior and famous for performing small miracles, welcomes them into her community and takes charge of them, but in reality, the nun is the epicenter of a series of horrors that will reach the girls in an attempt to bring the presence of the Evil One to Earth. After suffering horrors, rituals, and violations, the young women must bravely face their destiny to survive.