Buried is a nerve-shredding thriller with a title hiding an unexpectedly shrewd dual definition — descriptive of a man attempting escape from a belowground coffin in Iraq and, if he succeeds, what his incredible story likely would be within weeks.

Buzz on Buried was built in early 2010 after a rousing reception at the Sundance Film Festival, but its theatrical release played out against rescue efforts for trapped Chilean miners — real-life men for whom the world cheered, but who could have become collateral damage as easily as they earned coronation and compensation. Rodrigo Cortés’s film reflects such rigidly grim odds with relentless discomfort — assisted by superior sound design, creatively claustrophobic camerawork that intimately introduces every knot and grain of the pine-box setting and a one-man-show from Ryan Reynolds, who leaves no room for sarcasm in this sarcophagus.

Reynolds’ celebrity spawned from blending amiable-bro humor with action-hero oomph and displaying ab-slab beefcake when necessary. But the palpable anxiety Reynolds conjures in Buried feels revelatory — hair matted by blood, sweat and dirt and actions driven by panic, disbelief, rage and, ultimately, proactive measures.

After an opening-credits shout-out to Bernard Herrmann’s pulsating strings and Saul Bass’s gob-smacking geometric trails, Buried cuts to black. One by one, we meet Reynolds’ main co-stars — sound editor James Muñoz, cinematographer Eduard Grau and set physiotherapist Javier Guerra (who certainly earned his keep). Shuffles, scratches, wheezy breathing, the click of a fumbled-for Zippo. This hollow void doesn’t frazzle quite as much in the living room as it does in a blacked-out movie theater’s forced tunnel vision, but it still conveys an immediate desperation.

Paul Conroy (Reynolds) is a civilian truck driver for an American defense company who awakens to this nightmare. A terrorist’s call to a partially charged BlackBerry (with supernatural signal strength) in the coffin with Paul ends with a ransom demand for millions of dollars within a small window of time. It also propels Paul’s racing mind to piece together not only who kidnapped him, but also who might have reason to leave him there. He isn’t only contending with a ticking clock, America’s intractable terrorist-negotiation tactics and dwindling oxygen, but his captors’ increasingly morbid demands. Chris Sparling’s script sinks its thumbs into the viewer’s windpipe, breathlessly spitting information while smartly considering the touchy political complexities of an international incident.

After trying to reach his wife, his employer and the FBI, Paul eventually gets on the horn with a State Department agent, and in their affecting exchanges, Paul learns he must conserve morale and battery power. Both are truly tested in a later phone call with someone else (whom character-actor enthusiasts will instantly recognize as a voice that can, at that stage, only be motivated by gutless evil).

Cortés employs slightly unfair, though visually expansive, computer-generated trickery to move the camera in an otherwise unreasonably constrictive environment. But he plants the camera squarely on Reynolds’ face for the climax, which helps hammer home the unforced, subtle wartime commentary of Buried: Civilians chasing their own high-risk, high-reward piece of war profit do so at their own peril.

Buried arrives in a combination Blu-ray/DVD package. For a film purposefully drained of all color and contrast flourishes, Blu-ray might seem superfluous, but its lossless 7.1 DTS-HD sound offers the premier presentation. Sounds like a vibrating BlackBerry, flickering flames and falling sand particles receive appropriate weight, given the confined space. And the surround field is fully engaged during the imageless opening sequence.

There’s little in the way of extra material, save for theatrical trailers and Unearthing Buried: The Making of Buried — a featurette that discusses how Cortés and company worked around the film’s restrictive, subterranean setting.