When reading the title, someone might ask: "WHAT IS THE UNBELIEVABLE FIB?" It's the question printed on a card that eleven year old Prudence Potts has just received. On the other side is a message: "Be grave in your search and avoid having stones in your head." No one but Pru can see the card--except for the new boy, Abe, who moves into town after the cards arrive. It soon becomes clear that in the small New England town of Middleton, nothing (and perhaps nobody) is as it/they seem. There is a world of Norse mythology going around town, a mystery is brewing, and it is up to Pru to get into an investigation. I would rate this book 5 stars out of 5 because of this reason.