Uglies is a book series by Scott Westerfeld for young adults. Westerfeld originally intended for Uglies to be a trilogy. However, after publishing the series' first three novels, Uglies, Pretties, and Specials, he ultimately wrote an additional fourth book, Extras. This fourth book is dedicated "[t]o everyone who wrote to me to reveal the secret definition of the word 'trilogy'." On February 2, 2018, Westerfeld announced a continuation of the series consisting of four new novels, the first one being Impostors, that was released in September 2018.
The first three novels focus on the exploits of Tally Youngblood. In the post-apocalyptic future society where Tally lives, teenagers, upon reaching their sixteenth birthday, undergo a surgery to mold them into a so-called “Pretty.” When Tally's new friend Shay runs away to the Smoke, a secret refuge for those who oppose the city's government, the future of Tally's own operation becomes uncertain. Dr. Cable, the head of the mysterious Special Circumstances, cuts Tally a deal: betray her friends and help the city locate the runaways or remain an "Ugly" forever. When Tally joins the Smokies, she learns a chilling truth: the surgeries that the city performs are not just intended to render its inhabitants beautiful. The city also puts lesions into the minds of the "Pretties", making them shallow, unintelligent, and ultimately an easier to control population. Over the course of the novels, Tally struggles to maintain her sense of self within a society that literally alters how people think and ultimately succeeds in undoing the system of mind alteration.
The fourth novel centers on Aya Fuse, a girl struggling to find her place in the chaotic world after Tally frees people to think for themselves.