In 1985, mountaineer Joe Simpson and his climbing partner Simon Yates were descending Siula Grande in the Peruvian Andes when disaster struck. Joe fell and shattered his leg—a near-certain death sentence at such high altitude. Simon bravely tried to lower him down the mountain using ropes, but during a blizzard and with no visibility, Joe slipped over a cliff edge and was left dangling. Unable to communicate and fearing they’d both die, Simon made the agonizing decision to cut the rope. Joe fell