>Regular horror game
Protagonists discover that the small commune has barbaric traditions involving the horrific, drawn out torture of innocent maidens. This causes shit to be haunted.
>Project zero game
Protagonists discover that the small commune has barbaric traditions involving the horrific, drawn out torture of innocent maidens. However this is absolutely necessary because we're sitting on some kind of primordial hellish darkness we need to seal/appease. Shit's haunted because someone grew a heart and didn't do the horrific torture properly.
This is essentially the plot to all five games.