Determined to keep Annabelle from wreaking more havoc, demonologists Ed and Lorraine Warren bring the possessed doll to the locked artifacts room in their home, placing her 'safely' behind sacred glass and enlisting a priest's holy blessing. But an unholy night of horror awaits as Annabelle awakens the evil spirits in the room, who all set their sights on a new target, the Warrens' ten-year-old daughter, Judy, and her friends.

A priest with a haunted past and a novice on the threshold of her final vows are sent by the Vatican to investigate the death of a young nun in Romania and confront a malevolent force in the form of a demonic nun.