After a highly publicized failure to complete a five-Ironman ultra-triathlon, endurance athlete Will Turner sets out on a 914-mile race unlike anything attempted before. Beginning with a 15.6-mile swim in Lake Tahoe, followed by 728 miles of cycling over brutal Sierra mountain passes, and ending with a 170.4-mile run near Mammoth Lakes, Turner battles fatigue, sleep deprivation, and unforgiving weather. With redemption on the line, he must push beyond his limits to conquer what may be the toughest ultra-triathlon ever created.