Some true survival stories are so unlikely and outrageously unbelievable that no Hollywood screenwriter could ever dredge up such material. Often these almost mythical tales of men and women overcoming great odds showcase astounding individual conviction and the iron will to live. These stories usually reside within harsh conditions of the earth’s deadliest environments, places that evoke a sublime natural menace. The chilling events depicted in Kevin Macdonald’s harrowing new documentary “Touching the Void” more than scratch the surface of such a journey and place. The film pulls you in headfirst.

This story, like most that spell disaster on the horizon, begins with an obsession. In 1985, Joe Simpson and Simon Yates, two bold and skillful British mountain climbers, set off to conquer the west face of the never-climbed Siula Grande mountain in the Peruvian Andes. These men have an addiction to the physical and mental prowess high-pressure situations call for. The fresh air and the open terrain elicit a rush of adrenaline unlike anything else.

The climb up the face begins and ends quickly and without any delays. However, like Joe says, “Eighty percent of accidents happen on the descent.” After a quick celebration at the summit, Joe and Simon begin to make their way down. Soon, they find themselves bogged down by a snowstorm and lost. Joe ends up severely breaking his leg and Simon must make a decision of whether to cut his friend loose or die with him. To go any further into the story would belittle the incredible trek each man ultimately takes.

Told with modern-day personal interviews and startling re-enactment footage, “Touching the Void” captures the two men’s last grasp for life in a place unmatched in its frigidity and fury. The two depend on each other to survive; however, each must make a choice regarding sacrifice. As the men’s voices overlap the recreated scenes, their painful memories resonate with tragic haziness. Even though the images we are seeing aren’t real, Macdonald’s camera puts these men’s words into motion, scraping along with every frozen step.

Kevin McDonald, who won an Academy Award for his great documentary “One Day in September,” has fashioned a unique hybrid of on-location visual re-enactment and primary source information. The two men seem eager to share their journey with the filmmakers, dutiful to explain their decisions carefully and form a structured way to cope with trauma and guilt. Ultimately, “Touching the Void” can’t help but revel in the beautiful on-site shooting, even moving more toward a straight narrative with musical cues and slow methodical editing.

However, the human aspects of “Touching the Void” will remain foremost in the minds of those who experience Joe and Simon’s plight. In the midst of rock-hard ice covered by dangerous formations of powdery snow, the two men find solace in the fact that they trusted each other, never once flinching into the realm of doubt. As climbers, Joe and Simon knew each other well, but over the course of the seven days “Touching the Void” depicts, they are forced to see each other as pillars of survival, constantly hanging on to each other for dear life.