“Meru” documents the expedition of Renan Ozturk and two other climbers on their Himalayan quest. (Jimmy Chin/Music Box Films)

Before 2011, no one had ever climbed to the summit of the “shark’s fin,” a blade-like outcropping of ice-and-snow-covered rock rising to a height of 21,000 feet from the back of Mount Meru in the Himalayas. Several had attempted it and failed, including Conrad Anker, Jimmy Chin and Renan Ozturk, whose team ascent, in 2008, took them within 100 meters of the top before they turned back in defeat, starving and half frozen.

The documentary “Meru” is the edge-of-the seat story of their return three years later for a second go at the treacherous peak. Directed by Chin and Elizabeth Chai Vasarhelyi — with footage from the 2011 climb shot by Chin and Ozturk — the movie is no less harrowing for the fact that the visual record of the attempt is supplemented by after-the-fact interviews with Anker, Chin and Ozturk. Knowing that the men didn’t die is comforting. But there is still great suspense in watching their effort, and in not knowing whether (or how) they would make it.

The more interesting question, of course, is why they would even try. “Now why do we do this stuff?” asks Anker, rhetorically. “The view.”

He’s joking, as it turns out, despite the fact that the scenery is breathtaking, as evidenced both by the climbing footage and supplemental aerial photography. There must be some other powerful attraction to the challenge that has to do with its very impossibility — in fact, with the likelihood of death — that pulls these men. And when the film gets into this thorny question, via the philosophizing of mountaineer and writer Jon Krakauer and others, the film is at its most fascinating. There’s a kind of terrifying yet beautiful insanity to what we are being shown here, which is as much a tale of unearthly willpower as of superhuman physical effort.

The structure of the film, which begins with the aborted 2008 climb, helps raise the stakes for the story, which culminates in the 2011 return to the mountain by the three men. Near-tragic events between the climbs — including an accident in which Ozturk was almost killed on a different mountain, and Chin’s hair-raising escape from an avalanche — reinforce the risks of what they are attempting. Chin’s description of how he was nearly “crushed under an ocean of car-size blocks going 70 miles per hour down a 2,000-foot slope” does wonders to focus the viewer’s mind on the immediacy of death in the sport of high-altitude climbing.

One theme that surfaces, again and again, is the idea of trust. The bond between these three men is spoken of repeatedly. But it’s also something we feel, almost viscerally, in Chin and Ozturk’s sometimes intimate camerawork, which zeros in on bowls of frozen rations as often as it takes in the panoramic scenery. “Meru” can evoke a sense of claustrophobia (and other fears) in the viewer. But just as often it gives rise to awe, wonder and amazement at what man, when he puts his mind to it, is capable of.

R. At area theaters. Contains coarse language and suspense.
90 minutes.