In 1985, Joe Simpson and Simon Yates, young and skilled climbers, set out to climb the west face of the Siula Grande in the Peruvian Andes, a feat that had previously been attempted but never achieved. Disaster strikes when Joe falls a short distance and breaks several bones in his leg. With no hope of rescue, the men decided to attempt the descent together with Yates lowering Simpson 300 feet at a time in a slow, painful process that could have potentially been deadly for both. When Joe goes out over an overhang with no way of climbing back up, and certain they were about to be jointly pulled to their deaths, Yates makes the decision to cut the rope and let his friend fall.