As a horror fan, I have spent many years waiting for just one quality horror movie without compromise. God knows I browse Netflix and wonder if I'd rather see something that might not be made all that seriously or one that was probably made with a serious intent. Here, we have a truly solid entry. There's a well-timed opening that establishes the horror entity and then a gradual reveal of who or what the entity was/is. There's a personal story about a sister choosing to take care of her brother because her mother is psychologically ill that feels sincere. I also like how the movie retains a sense of being unpredictable. Overall, the themes are set up and explored efficiently, there are some excellent scenes, and the movie builds to a darkly beautiful finale. There's a great sense of place as the director establishes the areas and then has the characters act in the areas so that we know where they are in the structure of the house rather than just being a 'scene' away from the other characters. Elizabeth Shue is reliably fantastic.
Just FYI, I prefer to just watch a movie without watching trailers or reading much beforehand which is why this review does not describe much in detail. This is a perfect horror movie to just watch without watching anything beforehand and see if you enjoy it. Many movies are best experienced that way. The only thing I had a slight issue with is that you are just buying a blu-ray with a digital copy, no DVD. I personally keep the DVDs and give them to friends and family to rent/keep, and this was one in which I was excited to share the movie. Ah well, at least I got a blu-ray and a digital copy. And one of at least ten solid horror flicks to be released in the same year.