Seriously underrated movie. I watched the original version with Spanish subtitles, and in my opinion it is the best way to watch. Anyway, if you expected cruelty and horror prepare to not be disappointed because seriously, this movies delivers! With that being said, it does have it's lacks, first of all this is obviously meant to be the beginning of a franchise (you'll realize that after watching the cliffhanger ending), nonetheless, this small production Argentinian movie is not afraid to hurt anybody's feelings. What I can tell you for certain is that this is the best it gets, just don't expect the sequel to be half as good.
Review of When Evil Lurks
