For the last 19 years, Tim Friede, a truck mechanic from Wisconsin, has endured more than 200 snakebites and 700 injections of lethal snake venom—all part of a masochistic quest to immunize his body and offer his blood to scientists seeking a universal antivenom. For nearly two decades, few took him seriously. Then a gifted young immunologist stumbled upon Friede on YouTube—and became convinced that he was the key to conquering snakebites forever.