In 1999, after a series of adventurous jobs--working construction at the South Pole, ranching in Montana, fighting wildfires in New Mexico, and sailing private yachts around the world--Sam Sheridan found himself in Australia, loaded with cash and intent on not working until he'd spent it all. He quit smoking and began working out at a local gym, where it slowly occurred to him that now, without distractions, he could finally indulge a long-dormant obsession: fighting. Within a year Sheridan landed in Bangkok to train at the legendary Fairtex gym with the greatest fighter in muay Thai (Thai kickboxing) history. Driven by a desire to know what only a fighter can--about fear and violence, about the dark side of masculinity, and most of all about himself--he stepped through the ropes for a professional bout. That single fight wasn't enough. Sheridan set out to test himself on an epic journey into how and why we fight. From small-town Iowa to the beaches of Rio, from the streets of Oakland to the arenas of Tokyo, he trained, traveled, and fought with Olympic boxers, Brazilian jiu-jitsu stars, and Ultimate Fighting champions. A Fighter's Heart is the dazzling chronicle of Sheridan's quest. In part, it's an insightful look at violence as a career and as a spectator sport, a behind-the-pageantry glimpse of athletes at the top of their terrifying game. At the same time, it's a dizzying firsthand account of what it's like to reach the peak of finely disciplined personal aggression, to hit--and be hit.