Just watched this. A really interesting horror film based in rural Argentina.
It's a 'demonic possession' genre film which treats possession more like an infectious disease, in that it can travel between people and even animals.
Killing a demonically infected person is a sure fire way to be possessed yourself.
It was pretty good, lots of over the top violence and gore and some tense atmospheric scenes.
Tons of plot holes if you think too much about it, but a really enjoyable popcorn horror non-the-less.