When a nun in a cloistered abbey at Romania takes her own life, a priest having a past and a novitiate on the threshold of her vows are delivered by the Vatican to explore. Together they uncover the unholy secret of the order. Risking perhaps not only their own lives but their own faith and their very souls, they confront a malevolent force at the kind of the identical demonic nun that first terrorized audiences at"The Conjuring 2" as the abbey gets a horrific battleground between the alive and the damned.