When Evil Lurks (Cuando Acecha la Maldad)

 This one is really special. I usually try to avoid spoilers in these posts, but When Evil Lurks really is a movie best enjoyed knowing as little as possible about it; Go watch it now, and if you need any prodding, know it's the best, most bleakly brutal piece of horror I've watched in a very long time.

  Still here? OK then: Pedro (Ezequiel Rodriguez) and Jaime (Demián Salomon) are two stupendously hirsute brothers living together somewhere in rural Argentina. While investigating a mysterious shooting in a neighbouring field, they find the body - the bottom half of a body, to be precise - along with some weird, occult-looking equipment. They ascertain that the deceased was headed for a nearby shack, and once they get there they find that the family living there are harbouring an 'embichado' (the english subtitles translate that as 'possessed', but 'bug-ridden' or 'infested' would be a better fit).

 Pedro and Jaime recoil with fear - not just because the embichado is a grotesque, swollen mockery of a man, but because apparently embichados are a known quantity, and it means very bad things. They don't share any of that knowledge with the audience, so we're left to gather bits of meaning from context and terse comments; There's talk of Bug-ridden people, something called Incarnates, and demons - the film puts its unique, apocalyptic spin on possession and runs with it.

 The worldbuilding (to use an out-of-favour word) in this movie is masterful. There are a couple of awkward exposition dumps later, but by then we've built up a picture of what's going on and they serve mostly to fill in some gaps. And it's not like the script is afraid to leave things unexplained or seemingly break its own rules; Its priority is to scare the everliving shit out of you, not give you the satisfaction of figuring out its lore.

 This is all demonstrated beautifully as the brothers first try to contain the evil, and then to outrun it (trying to save their family along the way). I can't overstate just how gripping and intense the first half of this movie is - and it features one of the most unbearably tense suspense sequences in recent memory. I can't imagine how that bit would play if you somehow don't figure out what's going to happen, but at a guess you'd miss out on the suspense but get the mother of all jump-scares.

 The good news is that the back half is still damn good. It loses a little of the first part's incredible momentum and makes a couple of minor missteps, but there's still plenty of fucked-up imagery and horrible shit to go around, and it steps up its game again in time for a ruthless litany of final scenes.

 Writer/director Demián Rugna carefully stages every scene for maximum effect, fostering a bleak sense of doom, that things will inevitably go to hell... and with admirable dedication to the mayhem that ensues when they do. Cinematographer Mariano Suárez and composer Pablo Fuu maintain the ambiance beautifully. This one... this one fucking rocks.