Room

There’s no getting around it. Room’s distinctive two-act structure and the indisputable fact that its second half is every bit as significant as the first leave me no choice but to warn that there will be spoilers.

I repeat: There will be spoilers. That’s the only way to do this remarkable film justice.

To proceed otherwise would be as pointless as reviewing Jaws and not mentioning a boat trip.

Based on Emma Donoghue’s 2010 novel and brilliantly adapted by the author, the movie starts as the story of a mother and 5-year-old son struggling to cope with the nightmare of captivity. Ma is 24 and has been a sexual slave for seven years, following her abduction from the streets of the town where she lived with her parents. She’s played with astonishing depth and fearlessness by Brie Larson, whose performance earned a Best Actress Oscar nomination.

Jacob Tremblay, who was 8 when the movie was made, is a small wonder, with instincts that make his Jack one of the year’s most unforgettable screen creations. In the film’s first half, we watch as mother and child go through the paces of typical days that are anything but. Ma reads to Jack, exercises with him, encourages him to draw and write stories, and makes him comfortable with the notion that the 10-by-10-foot shed in which they’re trapped is the entire world.

Having never stepped outside, he has no reason to suspect otherwise. “Hello, lamp. Hello, sink. Hello, stove,” Jack cheerfully begins each day, greeting the objects that are locked in with him as best friends. His mother shields him from the truth by nurturing an illusion of limitlessness, harnessing the power of their imaginations to transform their prison into an almost magical kingdom.

On the nights when Ma’s captor, known only as Old Nick (Sean Bridgers), visits to rape her, she shields Jack by hiding him in a small wardrobe. Incredibly, Room is based on real events, the 2008 case of an Austrian woman named Elisabeth Fritzl.

In the second half, we watch as mother and child struggle to cope with the shock of freedom. If anything, this is the more intricate and wrenching of the two acts. Dublin-born director Lenny Abrahamson (Frank) does a masterful job. In the first half, he employs special cameras to create a suffocating sense of claustrophobia; in the second, he captures the mind-blowing blast of space, movement, color and sound that threaten to overwhelm Jack. Which is why Abrahamson has received the Best Director nomination that Oscarologists predicted would go to Ridley Scott.

He doesn’t miss a detail in the scenes after Ma brings Jack to her childhood home to recuperate. We watch Jack negotiate stairs for the first time; how Ma’s father (William H. Macy) can’t bring himself to acknowledge her son; how her mother (Joan Allen) hangs back and gives Jack space to approach her on his own.

Then there’s Ma’s crash. Larson’s so good you can practically see the storm clouds gather behind her eyes. Donoghue’s screenplay doesn’t hit a false note as she charts mother’s and son’s contrasting reactions to life outside Room. Which is why it, too, is up for an Academy Award.

The Academy can nominate up to 10 films for Best Picture and this year selected just eight. Of the 691 movies domestically released in 2015, this one, with its modest budget and largely unknown leads, beat the odds to be one of those eight. Abrahamson’s film does the virtually unimaginable: It stares down inhumanity and emerges as an uplifting cinematic experience. Room won’t win Best Picture, but it will win your admiration. Maybe even your heart.

ROOM (4) Directed by Lenny Abrahamson • Starring Brie Larson, Jacob Tremblay, Joan Allen, William H. Macy • Rated R • 118 min. • At Century Cinema Del Monte, Lighthouse Cinemas.