Some secrets are hidden in perilous places, unforgiving landscapes inaccessible to all but a few intrepid individuals. In "Code of the Wild," Chris and Casey Keefer tackle rugged terrain and enter uncharted territory to track down the truth behind history's greatest mysteries. Plumbing the depths of caves and trekking through dense forests, the brothers deploy their survival skills and tracking techniques to answer longstanding questions. "I'm a history buff, and when it comes to unexplained mysteries I go digging for evidence, says Casey. "I use my love of technology to get us closer to the truth," adds Chris. "Our equipment helps us to go deeper and see clearer than ever before." Episodes follow Chris and Casey as they head deep into the Amazon to find a city of gold, trek into the heart of Alaska looking for the wreckage of a plane that vanished while carrying Reps. Hale Boggs and Nick Begich and hike into the Appalachian Mountains in search of a lost Confederate treasure.