To describe Touching the Void as a mountaineering documentary would be to do this breathtaking drama an injustice. By intercutting narration from the climbers themselves with a nail-biting reconstruction of their remarkable adventure in the Peruvian Andes, the film has the best of both genres: the authentic stamp of factual storytelling and the edge-of-the-seat tension of a dramatic movie.

In 1985, two British mountaineers, Joe Simpson and Simon Yates, embarked on a daring–arguably reckless in the extreme–attempt to climb the previously unconquered mountain Suila Grande. A mixture of overconfidence in their own abilities and underestimation of the climb’s difficulties brought them to grief after the successful slog to the summit. What follows is an often harrowing account of their perilous descent, during which Joe horribly shatters his leg and Simon is forced to cut the support rope on which Joe’s life, quite literally, is hanging by the proverbial thread. It’s no secret that both climbers lived to tell the tale, but at every stage the audience will be left guessing just how the crippled Simpson could possibly have found the inner strength to surmount each deadly trial.

Based on Joe Simpson’s gripping book, the film boasts glorious widescreen photography of Suila Grande and its notorious glacier. Actors take the place of the two climbers for close-ups, though Simpson did return to Peru in order to re-enact parts of his dreadful crawl back down the ice. The story of Simpson’s almost superhuman fortitude has become legendary in climbing circles, and even for viewers uninterested in mountaineering, Touching the Void is an astonishing slice of real-life drama, magnificently retold.