The trailer gave me the impression of having inter-dimensional themes, but then a review on Netflix says this:
The strained relationship between a mother and her teenage son turns tragic when the boy engineers a massacre at his high school, and the mother is forced to ask how much blame she deserves for the heartbreaking event.
Director Lynne Ramsay has a marvelous eye, a gift for strong visuals and a hunger for dark material. She was a bold but smart choice to adapt We Need To Talk About Kevin, the best-selling novel by Lionel Shriver. The book is nominally about a school shooting in America. But it's really about a reluctant mother (played with uncompromising skill by Tilda Swinton) who from the moment her child is born simply doesn't love him, simply isn't flooded with the emotions everyone assured her she would feel because "it's different when it's your own." For her, it's not different. It doesn't help that the baby seems to reject her too. She never stops trying to connect or understand the child even as she sees him growing into a disturbingly unempathetic little boy. Did she feel no love for him because he was born this way or did he become this way because she couldn't offer him the maternal love every baby deserves? This emotional journey is fitfully captured in the film, which is inevitably dominated by the school shooting itself and Swinton's miserable life afterwards in the community and her repeated visits to her son in prison. Is he human or just a monster? And is she a monster for not being able to love him? All of this is addressed visually and intellectually in the film, but the dots aren't quite connected emotionally. The film misses the career as a successful travel writer and businesswoman that Swinton sacrificed (it's alluded to briefly) and loses some of the impact of the climax by ditching the novel's narrative decision to have the mother address her husband in letters talking about their son. It's a film to admire, but not one that quite wrenches your heart out the way it should. And the horror of the killings (echoed too often with the color red dominating the film's palette) just doesn't let us focus on what made the book more than just a fictional Columbine: the horror of a mother who fears she never should have become pregnant in the first place.