Like its central location, "Room" is small and relatively quiet, but it manages to pack a massive emotional punch, alternately devastating and redemptive. And, even with a crowded month and a half left in 2015, it's a frontrunner for the best film of the year.

Like its central location, "Room" is small and relatively quiet, but it manages to pack a massive emotional punch, alternately devastating and redemptive. And, even with a crowded month and a half left in 2015, it's a frontrunner for the best film of the year.

Based on a novel by Emma Donoghue, "Room" tells a story through the wide eyes of Jack (Jacob Tremblay), a warm and optimistic 5-year-old boy who lives with his mother, known to him simply as Ma (Brie Larson).

While the loving interactions between a protective mother and her inquisitive boy are typical, their surroundings are not. Jack and Ma spend the entirety of their existence in a small underground space they simply call "Room."

The reasons for their captivity slowly come to light, as does the broad scope of their tiny reality.

I'm being purposely vague here, as I feel some of the stories written about "Room" have diminished some of the reveals for those who haven't read Donoghue's novel, but be forewarned that the basis of Jack and Ma's plight is dark.

The movie, on the other hand, is more light than dark. Much of its perspective is young Jack's, and the film shares his wonder at the simplest things. Jack's world is created and nurtured by Ma, and the scope of both her burden and her love come into focus with crushing effectiveness.

Director Lenny Abrahamson follows up the excellent and eccentric "Frank" with a film that pulls off an amazing feat. It runs a range of emotion and still feels like a coherent whole, even as its story becomes very different in a second half that is less tense but full of a different impact. His relatively young career has already made him a director I'd watch do anything.

Donoghue also adapted her own work for the screenplay, which is often a red flag. She manages to take the first-person narrative of Jack from the book and use it to punctuate rather than steer the onscreen story. I rant about how hard book-to-screen adaptations are. This is how it's done.

But the real reason "Room" left me the way it did - I'm comfortable enough to admit to being on the verge of tears for about half of its running time - is the lead performances. Larson bears the weight of Ma's situation with sweetness and stoicism for the sake of Jack, but the actress also knows when and how to release the pressure valve on what's beneath. And Tremblay gives a performance that feels real, a rarity among child actors.

Bold prediction: "Room" will leave you changed. That's the mark of an amazing film.

"Room"

Opens Friday

4 stars out of 4