Horseshoe Canyon Ranch is a sleepy patch of rural Arkansas where nothing much happens. Except for once a year, when hundreds of climbers descend on the place for 24 Hours of Horseshoe Hell, a climbing competition that’s a bizarre mix of Burning Man and Climbing magazine. When elite climber Alex Honnold shows up, he brings his A game. But he might not be prepared for two things: the level of rowdiness and a pair of underdog climbers.