A twelve-year-old kid in the audience raised his hand and asked, 'Aren't you afraid you're gonna die? 'Without missing a beat, Alex shot back, 'We've all gotta die sometimes.

You might as well go big.' Alex Honnold is 28 years old, and perhaps the world's best 'free solo' climber. When Alex performs one of his long free solos, the severity of which no one else has yet dared to attempt, he does away altogether with ropes, with a partner to catch his fall, with support of any kind (neither bolts, pitons, nuts or cams).

There is a purity to Alex's climbs that is easy to comprehend, but impossible to fathom; in the last forty years, only a handful of climbers have pushed 'free soloing' to the razor edge of risk. Half of them are dead. From the northwest face of Yosemite's famous Half Dome, to the frighteningly difficult El Sendero Luminoso in Mexico, Alone on the Wall is structured around Alex's seven most extraordinary climbing achievements so far.

These are tales to make your palms sweat and your feet curl with vertigo, told by a smart, likeable climbing visionary who, as Jon Krakauer says, is 'utterly genuine. There's no bullshit there.' But these stories also get to the heart of how - and why - Alex does what he does.