SPOILERS!
Due to the insane amount of requests for spoilers I've been getting, I thought I would just post the rundown here. Enjoy and share!
MAJOR SPOILERS FROM RECENT TEST SCREENING..........
Basically the movie plays as you see it in the trailer. It begins with Bella Thorne's character "Belle" moving into the Amityville house with her mom, little sister and her older brother James, who is confined to a hospital bed. Not too long after, strange things start to happen in the house, with one of them being her brother suddenly and seemingly recovered from his coma. Apparently 6 months earlier, James was driving drunk with Belle and a few friends, where they were in a terrible accident, leaving James a vegetable. Belle learns from her friend at school that the house they moved into was the site of a gruesome murder some 40 years earlier. Ron Defeo at this point had committed suicide in prison and according to the townspeople, his soul is lying in torment at the house. During this part, we(the viewers)begin to learn more about the history of the house, as well as some more backstory on Belle and her family. We learn that Juliet had a twin sister who died in her sleep 2 years prior, without any reasonable explanation, which was the reason her parents divorced. **NOTE** This is where I found the story to get "Jumpy" and confusing. I would bet this part was added on during the initial re-shoots to pad out the films run time.(the whole movie clocked in at around 92 minutes)I would also suspect that due to the new PG-13 rating, a good majority of this material was edited out, due to it's graphic content, Anyways, as she begins to investigate the murders and the house history, she starts to suspect that her mother knew all along about what happened in the house. The more and more she investigates, the more she becomes obsessed with finding out the truth. The last 15 minutes of the film is where things take a complete 180. It turns out that everything up to this point was all in Belle's head. We see through a flashback that right after her she broke through the red brick wall in the basement, she "awakened" Ron Defeo's spirit and he possessed her and through her she murdered her family just as he did in 1974. As since everything was in her head, everything we saw the whole movie was just her subconscious's way of dealing with what she had done and is now a new living vessel for Ron DeFeo's spirit. The last scene of the movie, while generic and done to death, was honestly quite effective here. Belle is now locked up in the mental hospital after presumably being found guilty of her families murder.(No Trial/arrest scene...lol it LITERALLY jumps to this scene. Bad editing perhaps?)The final shot of a "now possessed as Ron" Belle turning towards the camera as her face distorts just before she lunges at the screen. Fade to black.....