A subtle horror film not without its moments of suspense and utter creepiness. We follow Elena (accountant turned housekeeper, for some reason) who gets close to her employers (a couple who live in an isolated house without modern amenities, for some reason). She wants to save money quickly to go back to her son and so agrees to be surrogate mother for their baby.
The film was too slow for some, so if you need quick doses of jumpscares and shock tactics, this isn't one for you. However, I found the departure from mainstream action horror and script to be very refreshing. I was not bored at any point in the movie, because it does an excellent job of building character and relationships in the first half hour. If anything, I was impatient to see where it was all leading, because the story has some unpredictable turn of events.
Not a lot was answered by the open ending, so you need to pay attention to little details throughout the film, and theories will inevitably run amok with plenty of evidence for more than one horror scenarios. Also, it is always a good sign when you can sympathize will ALL of the characters (which are few to be sure, but very well played).
It is the most convincing horror movie to come out in a while, and I recommend it to anyone who can get roped into a horror story without a sense of urgency.