Important note: in this review I give a complete synopsis of my understanding of the story. Although there's a very good chance I got the story wrong, if I'm correct, I can't imagine a more spoiling spoiler. You have been warned.
INHERITANCE is a horror picture of the "slow burn" variety, or, perhaps, in the case of INHERITANCE, it would be more accurate to say "glacial burn". Getting all the way through the movie required a good deal of grim determination on my part and I can't really say that my stubborn patience was rewarded in the end.
As at least one other reviewer here has noted, the style of storytelling in INHERITANCE is most reasonably compared to THE SHINING although without that movie's style and panache. As in THE SHINING (in the movie version of the story), for example, there's no actual ghosts or monsters per se but more a collection of what are apparently interactive hallucinations and vague deleterious influences eventually resulting in some sort of insanity or other psychological collapse within the main character. Much of the cinematography is intriguing and even beautiful and provides a sort of jarring juxtaposition between the beautiful context scenery and the evidently growing mental meltdown. A dearth of dialogue, far less than in most movies, precludes much verbal confirmation or enlightenment about what's going on, leaving one mentally grasping for comprehension.
INHERITANCE relies heavily upon ambiguity and vagueness in order to accomplish its version of atmosphere; it is sometimes difficult to understand what's going on or what is supposed to be being conveyed in many scenes and it's simply human nature to feel unease when you're confused about the meaning of what you're seeing and exactly what it is supposed to be contributing to the overall story.
Because of the aforementioned ambiguity and vagueness, I may have misunderstood the story. But here follows a complete synopsis of my understanding.
A man with a pregnant significant other is suddenly informed that he has inherited a home from his biological father that the man had thought dead long ago. He and his significant other go stay at this home to check it out, most likely with an eye towards quickly selling it to create a nest egg for their new family. The inherited home turns out to be a gorgeous, sundrenched California beach home in a very upscale, apparently historic, area. Shortly after taking up temporary residence, the man begins acting strange and moody. Visiting an uphill neighbor he learns the context of the area is of pioneering white men moving in and taking over and taking Native American children to treat as personal property. Through hallucinations/visions, the man learns his biological mother was probably strangled in the home by his biological father acting under the influence of older spirit ancestors egging him on to do so. The man begins having visions/hallucinations of doing the same thing to his own significant other. The negative influences evidently originate from a magical Native American fetish figurine acting as a long-term revenge vehicle on the man's lineage. We recognize the figurine and the vision-men from old photographs found in the home. Driven by the increasing insanity from the influence of the fetish figurine, the man eventually commits murder while his significant other is away, burying the victim in the same hole in the yard in which his digging surfaced the fetish figurine. Man throws figurine over the backyard hedge out towards the beachfront and seems to have recovered. Inherited home is put up for sale, but in the course of packing the car to leave forever, he sees the figurine in amongst the items packed in the car. Noting its presence, he doesn't do anything but simply gets in the car and drives away with his significant other letting us know that the curse will continue. The end.
This represents my best guess at the actual storyline of the movie, but it's very difficult to tell if I'm correct. The movie is literally riddled with scenes that, though very picturesque and often beautiful, are hard to interpret as to what they mean within the story, and I would certainly be hard-pressed to make a decent case that half of the scenes in the movie arguably fit in my synopsis. What is the significance of all the scenes where the man stands on the beach in a wetsuit holding a surfboard but not surfing? What do the images of the man underwater floating around in kelp beds and staring at his father, also floating around in the kelp beds, mean? Who was the man who claimed to be a second cousin, and how did he know exactly where to find the fetish figurine at an arbitrary unmarked place in the backyard, and why would he be interested in it. I could go on virtually ad nauseam.
My best guess about the "second cousin" is that the screenwriter had no idea how to have the man find the fetish figurine depicted in the photographs and so just threw in the "second cousin" character to give the man somebody to kill and to tip him off where to dig for the figurine. The fact that it doesn't seem to fit and feels arbitrarily mysterious is no problem as far as this particular writer was concerned.
And I pretty much give the same explanation for the crazy-lady uphill neighbor who, out of the blue with absolutely no reason to do so, gives us the exposition about the history of the locale, totally out of keeping with all the other MISSING explanations, a la deus ex machina. If the writer didn't just stick her in there to give us a drizzle of explanation, which he never does anywhere else, there would have been NO HOPE whatsoever of getting a clue about what was going on and we would never know the motive for the revenge-fetish-figurine.
INHERITANCE certainly has an air about it, and is often beautiful to look at, but apparently Tyler Savage is no Stanley Kubrick and he would've done his movie a service by making his story a little less vague and ambiguous. That fact that Mr. Savage with both the writer and the director may be the point where things went wrong.