To protect his family from Doomsday marauders, Rob is devising the ultimate booby-trap system. He's securing his Texas property's perimeter with an elaborate system of alarms, traps and defense mechanisms. In Tenn., Greg is preparing for a financial catastrophe by building an invisible tree house where he hopes to be safe from looters. If the build goes as planned, his family will have a tree house 12 feet into the forest canopy, with mirrored paneling and a stockpile of food, water and ammo.