In 1956, in a remote and dark convent in France, a peculiar combination of faith and terror comes back to life. Following the chilling events that shook a small village, Sister Irene has managed to leave behind the horrors that tormented her. However, peace is fleeting, and a new threat looms over her. As she tries to live a quiet life, she finds herself dragged back into the center of a struggle that tests her faith.
With the arrival of a new companion, Father Maurice, the visions of a malevolent spirit are resurrected. This being, an echo of the evil they had previously faced, seeks revenge and feeds on the deepest fears of its victims. Thus, the duo embarks on a dangerous mission to uncover the origin of this supernatural force, delving into a labyrinth of dark secrets and ancient rituals that will push them to their limits.
As demonic entities begin to manifest and torment the nuns of the convent, Irene and Maurice realize that their only hope lies in combating not only the creature but also the very internal demons that haunt them. The struggle between light and darkness reaches a chilling climax, confronting them with decisions that will change not only their lives but also the fate of those they have sworn to protect.