Along the way, he discovers the presence of Valak (the demon introduced in The Conjuring 2) and is forced to battle the supernatural to save the soul of a nun named Sister Irene (Taissa Farmiga).
The Nun is set years before the events of Annabelle: Creation, making it chronologically the first entry in the Conjuring universe.
Annabelle: Creation teased the eventual storyline of The Nun last year, so having James Wan (essentially the point man of this entire fictional landscape) get as hands-on as Corin Hardy explained in his interview with EW likely helped in the long run.
Set at a church in Romania in the early 1950s, the film follows a priest (Alien: Covenant actor Demian Bichir) as he investigates a mysterious haunting after the death of a nun.