In an increasingly secular world, people often look back on the past with a mixture of amusement and disdain: "Why," they ask, "would our ancestors really believe in fanciful things like demons, Gods, spirits and angels?" Yet in tonight's episode, Ben, Matt and Noel discover one strange trend that calls these assumptions into question: Why did so many ancient cultures across the world worship snakes, or reptilian-human hybrids? Is there a grain of fact to the legends of Snake Gods? What exactly is a Nāga?