You don't have to be claustrophobic to be unsettled by Lenny Abrahamson's latest film, a tale of love, hope and survival that confines a significant part of its action to a locked shed.
Said shed has been the home of Ma (Brie Larson) for seven years, the length of time she has been held captive by a man we know only by the demonic moniker Old Nick (Sean Bridgers).
The last five of those years have been spent raising Jack (Jacob Tremblay), a little boy for whom this single room represents the world in its entirety. Jack, to state the horrifically obvious, is Old Nick's son - a child born of rape who may be Ma's only chance of salvation.
The story may sound outlandish but it's based on a novel written by Emma Donaghue after hearing about the five-year-old boy Felix in the Fritzl kidnapping case, where a woman was held captive for 24 years by her father, repeatedly raped by him and delivered seven children.
Jack is routinely obliged to hide in Wardrobe to facilitate Old Nick's frequent visitations - encounters that we, like him, do not see but only hear taking place from behind a shuttered partition.
Jack, of course, has no awareness that there is anything outside the room that he's spent every minute of his life in - and they call it 'Room'.
And in this space, every object, like Table, Toilet, Lamp, Spoon and Sink, is not just a functional item but a friend. But no one is a better friend to him, of course, than Ma, and we watch with growing tenderness and trepidation as she attends to Jack's every need: running him through a morning exercise routine, playing games, reading books to him, giving him a bath, fixing a simple meal, and even baking him a cake to celebrate his fifth birthday.
Ma finally decides soon after this milestone that it's finally time to tell Jack the truth: 7 years ago, she was kidnapped by Old Nick ("He stole me," she explains) and imprisoned in Room. Two years later, Jack came along, and we immediately understand that this boy, despite the grim circumstances of his conception, gave his mother a reason to live.
Room is a film of two halves: life in Room and life beyond it. The first is the conditions that these two characters face in their claustrophobic environment, while the latter shows them finally stretching, embarking on new experiences, to assimilate themselves back to the conditions of normal society, fighting the demons that linger beneath them with a mixture of confusion and vulnerability.
The performances are exemplary and moving. Larson gives a powerful performance, which has earned her a Golden Globe, with more prizes potentially on the way. She's a resourceful, fiercely watchful Ma, utterly focused on her child and ways to keep him safe.
Tremblay gives a delicate, naturalistic performance, responsive and quick, as a trusting child with an essential optimism, no matter what he faces. The emotional depth and maturity of his portrayal is jaw-dropping. In on scene, when he sees the blue sky stretching on endlessly for the first time, he manages to emote the fear and excitement of stepping into the unknown beautifully.
The cinematography allows for objects and spaces to be concealed, lensed with dingy, muted colours and tight close ups that deliberately frustrate the viewers sense of space.
The camera perspective works with the perspective of a young child, and as a result we are in Room with the characters, and it feels big. We learn the truth along with the child and as the truth gets bigger, the room gets smaller.
The film is nominated for four Oscars, including Best Picture, Best Director and Best Actress for Larson - which she deserves to win.
Tremblay deserves a category of his own.
Room may be a film about entrapment, but it's also one about liberation, about letting go of one's fears and moving on from trauma.
At one point Jack asks to be shorn of the hair he has been cultivating since infancy. It's a revelatory, transformative moment in a film you won't find nearly so easy to say goodbye to.