Tally lives in a world where your sixteenth birthday brings aesthetic perfection: an operation which erases your flaws, transforming you from an 'Ugly' into a 'Pretty'. She is on the eve of this important event, and cannot wait for her life to change. As well as guaranteeing supermodel looks, life as a Pretty seems to revolve around having a good time. But then she meets Shay, who is also fifteen - but with a very different outlook on life. Before her operation she plans to escape to a community in the forest - the Rusty Ruins - where Uglies go to escape ' turning'. Tally won't be persuaded to join her, as this would involve sacrificing everything she's ever wanted for a lot of uncertainty. When she is taken in for questioning on her birthday, however, Tally gets sent to the Ruins anyway - against her will. The state wants her to go on an undercover mission and report back about the location of the community; otherwise she will forfeit her birthday operation. What she discovers in the Ruins reveals that there is nothing 'pretty' about the transformations...