Australian adventurers Cas & Jonesy battle alligators, deadly snakes, fatigue and each other in search of a lost trail through Georgia's infamous Okefenokee Swamp. The fearless world-record-setting duo have conquered the South Pole and crossed the treacherous Tasman Sea in a kayak but tackling the Okefenokee brings new and unfamiliar challenges. Hostile spirits - the ghosts of long-dead Native Americans - are said by the locals to roam dark corners of the wetlands and Cas and Jonesy must go.