In high-end modern rock climbing, 5.15 is the top of the difficulty scale, a grade achieved by only a few men and never by a woman. Margo Hayes, a little known 19-year-old from Boulder, Colorado, is determined to break with this tradition. To be closer to the world’s hardest routes, she has moved to Europe, where she trains and climbs with the goal of succeeding on two of the most iconic 5.15s in France and Spain. But by pushing her body and mind to the absolute limit, she risks injury and failure in her quest to be the first.