This book is an insider's guide to the world of Uglies. This book explains where Scott Westerfeld got his ideas for this book. It has maps, history, a glossary, and explanations about various things. It even has a hoverboard manual. It shows how they go through the life stages (littlie, ugly, new pretty, middle pretty, late pretty). It also talk about phi, the golden ratio. Phi is what he used for a pretty's face. He tells how phi and the Halo Effect are closely related. Westerfeld also explains the many inventions created for the series. He explains the slang used in the book and where he got the names for his characters.