Beginning with one very grim human condition, “Room” takes us into a small isolated world of its two main characters who have depended only on each other for years. While we are horrified by the darkness of their terrible circumstance, we are also touched by their intimate relationship which has been a tiny but precious light during their many unimaginable days of captivity, and the movie becomes all the more powerful as observing the resilience of their deep mutual love which leads them to the possibility of hope and salvation in the end.

In the beginning, we watch the daily routines of ‘Ma’ (Brie Larson) and her young son Jack (Jacob Tremblay), and we gradually gather the stomach-churning horror of their living condition. Ma has been held as a captive since she was kidnapped by some very twisted guy seven years ago, and Jack was the result of his frequent sexual exploitation on her. While never telling him about his biological father, she has raised Jack alone with some assistance from her captor, and the occasional warm smiles on her weary face tell us how much she has lived through her son as a way of surviving through her seemingly endless captive status.

For Jack, their small space, called ‘the Room’ by them, is simply the whole world he has been comfortable with since his birth, and he innocuously describes to us how he came into the world, while not being aware of the horror behind his birth and his abnormal childhood years. He learned well how to speak and read thanks to his good mother, but she has told him that nothing is real beyond their room, and he believes her words without any question even though the young inquisitive mind of this five-year-old kid roams around inside the Room from time to time.

And we also meet “Old Nick” (Sean Bridgers), a monstrous man who has been locking Ma and her son inside a garden shack in the backyard of his house located in some suburban neighborhood. Whenever he is about to enter the shack, Ma puts Jack in the closet for a while, but that does not completely shield her predicament from Jack, who, like any other child in his age, is curious about what is going on outside the closet.

Through his close, intimate approach to the story, the director Lenny Abrahamson, who previously directed offbeat comedy film “Frank” (2014), sticks tightly to Ma and Jack’s isolated environment. We are immersed into their limited viewpoint as the cinematographer Danny Cohen’s camera usually stays close to them as if it were another captive in their space, and Abrahamson’s two lead performers are believable in their unadorned but captivating portrayal of a human relationship under an extraordinary circumstance. The screenplay by Emma Donoghue, who adapted her acclaimed novel of the same name, is an engaging mix of pathos and innocence, and the movie also works as a nail-biting thriller when Ma begins to realize that she must do something very risky for herself as well as her son.

After I came to notice her small supporting turn in “The Spectacular Now” (2013), Brie Larson has been a new talent to watch. While she has continued to draw my attention through her supporting roles in “Don Jon” (2013) and “Trainwreck” (2015), she was particularly good as the earnest heroine of “Short Term 12” (2013), and the scene where her character silently shows her empathy and understanding toward one of the troubled kids under her supervision was one of the most moving moments in that small gem.

In “Room”, Larson gets another good opportunity to utilize her talent, and she is quietly heartbreaking in her plain but haunting embodiment of her character’s accumulating pain and exhaustion. Carefully balanced between resignation and stubbornness, her unpretentious performance subtly conveys her character’s persistent struggle against her gloomy situation, and that is exemplified well by a brief scene where Ma tries hard for any chance of rescue along with Jack. As they are ‘playing’, the scene chillingly implies that they did this many times before, and that further accentuates how much they are isolated from the outside world by their captor, who may wipe out their existence forever someday if that suits him.

As the movie puts more emphasis on Jack’s awakening on the true nature of his closed environment, Jacob Tremblay becomes more prominent as his adult co-star’s equal acting partner, and this remarkable young actor gives an astounding performance to strike us with its considerable emotional depth and clarity. While being cheerful and innocent under his mother’s protection, Jack is not a mere cute stereotype at all, Tremblay is confident and electrifying as a smart, sensitive boy who learns and grows everyday in spite of the restrictions imposed upon him.

Tremblay and Larson never take any single wrong step as they push or pull each other in the vibrant depiction of their characters’ relationship. When Ma and Jack clash with each other over what is really real or not at one point, their conflict and pain feel palpable to us as the camera alternates between the powerhouse actings by Larson and Tremblay, and then there comes a tense sequence in which Jack must be very brave as he follows his mother’s desperate measure for what may be their last chance of rescue.

Because the trailers and advertisements of the film do not hide it at all, it is not much of a spoiler to tell you about the eventual narrative turn in the middle of its story, but I let you appreciate for yourself how the movie precisely and exquisitely handles this dramatic transition. All I can tell you is that it is alternatively heart-pounding and heart-warming with the frequent close-up shots of Tremblay’s expressive face, which tells so many things including his character’s overwhelmed state of mind in front of a wide open world he has never seen before.

In contrast to the dark, moody tone of the first half of the film, the second half of the film feels warmer and sunnier in comparison as Ma and Jack are finally free and safe in the outside. While they are recovering at a hospital, we meet Ma’s parents, who must have gone through their own hard time after their daughter was gone missing. Nancy (Joan Allen) welcomes her returned daughter and her grandson into her cozy home, but Robert (William H. Macy), who is not living with his wife now, is a little more reluctant to accept this changed circumstance.

We now observe Ma and Jack’s slow, difficult rehabilitation process, and it is harrowing to see how they are still not entirely free from their former condition. Jack is often bewildered by his new world which is far more open and comfortable, and he sometimes misses his former world where there were only him and his mother. Tremblay is achingly tentative as Jack takes his first steps into the world outside, and it is touching to see how quickly Jack adapts himself well to his new environment. Kids are vulnerable indeed, but they always surprise us with the resilience in their young plastic mind, and what Tremblay achieves here is as memorable as Abraham Attah’s strong work in “Beasts of No Nation” (2015), which is another unforgettable child actor performance of 2015.

While humbly letting her young co-star take the center, Larson is devastating as her character struggles with her psychological wounds. Acutely aware of many lost years during her captivity, Ma, whose real name is Joy, frequently feels angry and confused while trying to process the changes in her and her son’s life, and Larson wisely does not overstate her character’s inner turmoil during a painful scene where Joy faces difficult questions about the ordeal she does not fully recover from yet. Thanks to Larson, Tremblay, and Abrahamson’s honest, thoughtful direction, it is genuinely poignant to see how Joy comes to regain her strength through her dear son, and that is another touching moment in the film.

With Tremblay and Larson as its heart and soul, “Room” comes to us a heartfelt drama of powerful human emotions, and it is certainly one of the best movies of 2015 in my inconsequential opinion. Remembering how much I was moved during its finale accompanied with pure elevation, I am now reminded of what William Faulkner once said: “I believe that man will not merely endure: he will prevail.” When the movie is over, you will see that he was right.