Unique in their beliefs, motivations and strategies, explore the lives of four families preparing for the end of the world as we know it. From bunkers to fortified off-the-grid locations, these Doomsday Preppers will go to whatever lengths they can to make sure they are prepared for any of life's uncertainties. And with our expert's assessment, they will find out their chances of survival if their worst fears became a reality. (Source: National Geographic Channel)