In each book, Poundstone seeks to explore a number of mysteries, and reveal "the uncensored truth about all sorts of stuff you are never supposed to know" (the series' tagline and the first book's subtitle).
Some of the mysteries Poundstone explores are urban legends (such as what happened to Walt Disney after his death), while others are day-to-day matters which many people may not think to contemplate, such as what barcodes mean, the Coca-Cola formula, secret airfrequencies, or what makes up KFC's 11 herbs and spices recipe.