Inventors, explorers, athletes, scientists, and mystics of the kinesthetic realm speak on the subject of sport, the environment, creative pursuits, religion, neuroscience, fear, flow, mortality, and discovery – one who walked on the moon, marginal characters who helped to make mountain biking mainstream, a B.A.S.E. jumper, a boulderer, Gidget, and those many others who would harness the power of play for oftentimes transformative ends.

Who invented the bungee jump? What are the limits of human endurance, of speed up a mountain, or survival at sea? How did it all begin? What motivates those who go in search of the unknown? Where will it end, and what's the point of it anyway?

"It's the spirit of innovation and anti-conformity and doing things differently," says Alexander Rufus-Isaacs, a founding member of England's Dangerous Sports Club (an experiment in weird adventures and alternative sporting events). "A manifestation of joy," "a Don Quixote adventure," "the most exhilarating moment that you'll ever feel in your life," and "a great step into the unknown," according to others.