Don't go into "La Llorona" for the horror of it, because you'll be disappointed -- horror is a by-product of any war atrocity, real or staged, and even though there are supernatural elements here that the title suggests, thus (also) rendering it a genre movie, these elements, they serve a different purpose. Frankly, I think it also being somewhat of a horror hurt its IMDb rating, because the wrong audience targets it and leaves it feeling misled. It's a good film on an important subject and you should see it.
Review of La Llorona
