What drives a person to the edge of one of the most difficult and revered mountains in the world? How much is one willing to sacrifice and suffer to pursue an authentic and bold life? The most accomplished mountain runner of all time, Kilian Jornet ponders these questions as he contemplates his record-breaking climb of Mount Everest, exploring the mountain’s changing nature over four seasons and his own existence. As he recounts a life spent studying, tending, and ascending the greatest peaks on earth, Jornet ruminates on what he has found in nature—simplicity, freedom, and spiritual joy—and offers a poetic yet clearheaded assessment of his relationship to the mountain . . . at times his opponent, at others, his greatest muse.