Lenny Abrahamson’s adaptation of Room does not set itself an easy task. Part of what made Emma Donoghue’s parent novel of the same name so entrancing—and so horrific—was its adept use of an immersive, childish perspective. Relentlessly, the novel frames a world and a mindset so frank, fresh, and convincing that the reader does not feel pressured to resurface. Donoghue’s text thrives on its ability to speak its own language, to frame desperation, survival, and adaption out of a nightmare scape. The book, on that front, does something extraordinary, resounding in the voice of a five-year-old child.

Abrahamson’s film follows closely the plot of Donoghue’s novel, almost step by step, as closely as a film adaptation could reasonably hope to follow. Jack (Jacob Tremblay) and Ma (Brie Larson) have lived in Room all of Jack’s five years of life. Ma, abducted from her college campus as a teenager, is the captive of “Old Nick” (Sean Bridgers), Jack’s father, and trapped in a soundproof garden shed that is the only world Jack knows. Outside, he believes, is Outer Space. Then Ma “un-lies”: she tells Jack the story of how she was stolen, and, as Old Nick loses his job and his abuse escalates, the mother and son make their escape. The novel—and the movie—hit their stride. One world meets another. Jack and Ma must learn to speak the language of the outside. Ma’s parents and their world have shifted, the lost world recovered, but altered.

But the film approaches this largely internal book with a medium that, unlike text, can only look out. The sense of scope—again, this is all Jack’s point of view—is so much easier to control in text than it is visually, on screen. Meanwhile the movie’s tangibility, its visceral details, stand out much more boldly than they do on the page. In film, we hear screams and see bruises only loosely understood, though clearly communicated, by Jack’s round-about narration in the book.

And remarkably the movie does just what it sets out to do. It’s faithfully, intensely accurate to the feeling of the book. Both are heart-rending. Both are impressive. Both go directly to the zone where narrative instinctually wants to shy away from, sinking back to the sidelines to imply the unspeakable. Instead, both movie and novel shove the most earnest and sympathetic child’s perspective into the heart of a very adult nightmare, and report directly. Donoghue has called her book an ode to motherhood, though that ode is delivered through moments of tight-throated drama; the movie saunters down that cathartic, quick-pulse path. The plot treads precisely through the heart of taboo, but does it—not for shock, and not for grandeur—with genuine heart. Part of this twinning, novel to screen, is likely due in no small part to the fact that Donoghue herself penned the screenplay.

The most obvious forays into the book’s limited, childish scope are close-ups and panning shots. These combine to bring our focus poignantly and specifically onto a single object. Objects in Room are characters themselves, in Jack’s eyes. They all have special personalities and special talents, all uniquely, intensely themselves, just like Jack and Ma. The movie brings that personality effortlessly to life: Jack greets each fixture in turn in the morning, establishing the scope of his Room-sized world. A film shot within a single space is not unprecedented by any means—Rear Window stands out, the most popular example. The camera pulls off a tricky set of maneuvers in Room, cutting from one angle to another, showing the room in sections, corners, and flashes. It isn’t minimized or boring, an hour into our time there, just the way that Hitchcock expanded the voyeur’s perch in Rear Window. We’re intensely aware of where we’re looking and how we’re seeing. Our window onto the novel’s world is as cleanly, expressly defined as in the text, through Jack’s eyes, in Jack’s scope.

Time also passes much more quickly in the movie: we aren’t trapped in Room for hours and hours, through descriptions and non-events, as everyday routines of exercise and cooking and bathing are condensed down to quiet montages. Room is expressed succinctly, as the movie rolls into its pacing.

The plot treads precisely through the heart of taboo, but does it—not for shock, and not for grandeur—with genuine heart.

Brie Larson’s energy fills up the screen during the opening hour of the movie, a grand, dynamic performance of forced cheer rushing into despondence into rage, entirely believable and entirely entrancing. Her performance makes this a powerhouse of a movie. Elastic and unbarred, she’s every inch the complexity and ferocity of Donoghue’s richly imagined Ma.

As for her costar, nine-year-old Jacob Tremblay, he communicates all the intensive focus that readers of the book will anticipate. There’s almost something a little unnerving about the intensity of Tremblay’s performance—especially in the moments when we see Jack, fresh in his expanded understanding of the world, trapped in disoriented and absolute panic. Between the two of them, Larson and Tremblay give their self-contained story its rich, human dimension.

The danger of such an excellent adaptation is that it runs the risk of becoming redundant for readers of the book. What is the motivation for having your heart ripped out by the same story in a new and more shocking way? And yes, the experience of the book is there, the ferocity of Ma’s love for her son, Jack’s adoration for his mother, his simple and articulate curiosity. The same heart-pounding suspense, the moments of tension. The movie is so fiercely attuned to the novel’s nuances that it comes as close to duplicating the experience of Donoghue’s magnetic little book as I’ve ever seen in an adaptation. Donoghue’s bottom-line observations ring true in the film’s tone: her clean, childish narrator observes “Ma hardly ever reads the no-pictures ones except if she’s desperate.” Desperation is what we understand; Jack does as well, though the pieces aren’t all in place for him. That’s the novel’s central, narrative trick, an instinctual leap. We move from clear-eyed Jack’s logic to the broader, adult logic of a moment, a leap that is both vital and nearly identical on page and screen.

The movie for a lover of the novel is not exceptionally new, but it is exceptional in its inventiveness, its faithfulness to a central sense of character and narrative. It’s a technical and emotional marvel. And it is certainly an experience. But it cannot, however, replicate an initial reading of the novel. The twists of the story, the moments of breath-stopping apprehension: that only happens once. And for book-readers, that moment happened the first time they encountered it in the narrative, the first time we watched Jack’s escape from and yearning for Room.

That is an issue faced by all adaptations, to a degree. The story they tell has been lived before, by those who read the book first. And for Room, what makes that repetition exceptionally pressing is the force of its story. The movie is certainly worth seeing, and worth admiring. But a repeat experience, in such identical terms to the book, runs the risk of feeling gratuitous. Movie and novel demand a little space from each other, a little room to breathe, to let each impress its own extraordinary experience.

Photo: Ma (Brie Larson), with her son, Jack (Jacob Tremblay)