In a convent, teenage orphan Justine forms a deep bond with Alucarda, who was raised by the nuns. When they encounter a mysterious gypsy in the forest, he is revealed to be Satan, who possesses the girls. Chaos erupts as the convent is consumed by darkness, impacting the lives of Alucarda, Justine, the nuns, and Father Lázaro.

Alucarda
The orphan girl's arrival at the convent unleashes a malevolent entity, threatening the lives of the nuns as a dark and ominous presence slowly takes hold.