In Mark Synnott’s unique window on the ethos of climbing, his friend Alex Honnold’s astonishing free solo ascent of El Capitan’s 3,000 feet of sheer granite is the central act. When Honnold topped out at 9:28 A.M. on June 3, 2017, having spent fewer than four hours on his historic ascent, the world gave a collective gasp. The New York Times described it as “one of the great athletic feats of any kind, ever.” Synnott’s personal history of his own obsession with climbing since he was a teenager—through professional climbing triumphs and defeats, and the dilemmas they render—makes this a deeply reported, enchanting revelation about living life to the fullest. What are we doing if not an impossible climb?