On a bright Saturday morning in September a young man is clinging to the face of Half Dome, a sheer 2,130-foot wall of granite in the heart of Yosemite Valley. He's alone, so high off the ground that perhaps only the eagles take notice. Hanging on by his fingertips to an edge of rock as thin as a dime, shoes smeared on mere ripples in the rock, Eminem blasting on his iPod, Alex Honnold is attempting something no one has ever tried before: to climb the Regular Northwest Face route on Half Dome without a rope. He's less than a hundred feet from the summit when something potentially disastrous occurs—he loses the smallest measure of confidence.
For two hours and 45 minutes Honnold has been in the zone, flawlessly performing hundreds of precise athletic moves one after another, and not once has he hesitated. In the sport of free soloing, which means climbing with only a powdery chalk bag and rock shoes—no rope, no gear, nothing to keep you stuck to the stone but your own belief and ability—doubt is dangerous. If Honnold's fingertips can't hold, or if he merely believes his fingertips can't hold, he will fall to his death. Now, the spell suddenly broken by mental fatigue and the glass-slick slab in front of him, he's paralyzed.
"My foot will never stay on that," Honnold says to himself, staring at a greasy bump on the rock face. "Oh God, I'm screwed."