This documentary tracks 13 contestants competing in the Badwater, the most extreme footrace on earth, which features a 135-mile course that extends across barren desert and three mountain ranges, with temperatures as high as 130 degrees Fahrenheit. Facing the added perils of flash floods and windstorms along the way, the brave participants run the full gamut of human emotions -- from joy to despair -- as they push the limits of human endurance.