We accept the world with which we’re presented.

Room, a wonderful little psychological thriller from Lenny Abrahamson, opens in limited release today. Its unique story of a mother and son stuck in an unthinkable circumstance offers a fresh perspective of how we look at our world and our family.

Jack (Jacob Tremblay) is celebrating his fifth birthday in Room – small concrete space where he spends all his time. He’s in Room with Ma (Brie Larson), his mother and the only other person he’s ever met. Room has a bed, a stove, a toilet, a refrigerator, a bathtub, a television and a wardrobe where Jack sleeps. We learn very quickly that Jack thinks Room is the entire universe and that Ma and another man, Old Nick (Sean Bridges) are the only people in the universe.

Slowly, Ma begins to unravel Jack’s perception of Room and we learn the dire predicament in which she and her son truly find themselves. It becomes apparent that Jack and Ma need to escape Room and that Jack’s entire universe is about to expand in ways that he could never fathom.

What seems like a simple story is actually an incredibly complex and multi-genred look at a terrible situations. It’s equal parts thriller, horror, sci-fi, and mother-son love story and Abrahamson juggles those perspectives expertly, never veering from the film’s strangely hopeful tone even as the story shifts drastically.

But this is not a film that grounds itself in story, instead Room roots itself in its characters. Where it would be so easy to turn this story into something overly sentimental or an “against the odds” story that would live better on Lifetime, the characters are presented with remarkable depth and insight into survival and recovery that completely de-romanticizes the pop psychology of trauma and those who overcome it.

The cast handles the complexity of their roles with aplomb. Larson is a rock hard force who slowly removes the layers of armor she’s used shield herself over the years without ever letting the audience too far inside. Yet she remains vulnerable and emotionally available throughout the frightening process.

Tremblay is equally outstanding in as good a child performance as you’ll ever see on film. His character is the audience’s way into a very bleak and difficult story and there’s a lot of responsibility resting on Tremblay’s very young shoulders. The natural nature in which he brings Jack to life is utterly believable and a main reason this film works as well as it does.

The one major flaw in Room is that it suffers from a letdown after its stunning first half. It’s almost like the air slowly seeps out of a very full balloon as we deal with a very long aftermath and Ma and Jack’s coming to terms with their decisions and new circumstances those have wrought.

That’s hardly enough to undermine the brilliance and originality of this film. Room is a very unique object and one that stays with you well after your first experience with it. Its unusual approach to a story that’s been fodder for much lesser fare and here it’s elevated far beyond its reaches.

Much as the world we’ve been shown to accept is expanded here.