Uglies is a young hero-adventure novel set in a dystopian future. The protagonist-hero of the novel is Tally Youngblood, a 15-year-old-girl on the verge of her 16th birthday. In this dystopian society, however, one’s 16th birthday is not just any birthday, it’s a date that marks a major change in a young person’s life—mandatory dramatic cosmetic surgery. Everyone in this society must undergo surgery to become a “Pretty,” a stylized version of a beauty that has been decided is biologically and scientifically determined as attractive. The hope is that if everyone is beautiful, no one will be discriminated against for their looks, and society will reach a utopian ideal of equality.

Tally falls right into line with her society’s ideas—she is a young hopeful who truly believes that once she turns into a “Pretty,” all of her insecurities and inner turmoil will be erased. Like any young teenager, Tally struggles with a sense of confidence and feelings of alienation in the world. When she meets, Shay, another “Ugly” on the verge of becoming a “Pretty,” she thinks she’s found an ally in her plight. They vow to be friends after the surgery, both realizing, with some confusion, that once someone becomes a Pretty, they never seem to return home.

It's Shay’s decision to run away that becomes the inciting incident of the novel that sets into motion the events of the novel. Shay, unlike Tally, is more skeptical of her society’s ideals and believes that one only feels “ugly” because her society prioritizes beauty in the first place, not the other way around. If society prioritized flaws, she argues, that would be the ideal. In other words—beauty is something that is fluid and varies with perception, rather than being a fixed biological ideal. Shay wants Tally to come with her to a place called the Smoke, where people live free of these tyrannical ideals of beauty. Tally politely declines.

But this is not the end of the road for Tally: Dr. Cable, an officer with Special Circumstances, and the novel’s antagonist is after Shay and wants to know the location of the Smoke. When she brings Tally in for questioning, she gives Tally a life-altering ultimatum: Infiltrate the Smoke or be denied surgery and be an Ugly forever. Tally reluctantly agrees, caving in to the social pressure of being an Ugly and social outcast forever. The hero journey she sets out on is not an honorable one, but rather a shameful one in terms of loyalty and friendship. But she feels she has no choice.

What Tally doesn’t realize is that her journey will teach her more than she realizes, and change her perceptions of her life, her society, and even beauty itself, something she was so certain of before. Tally makes the trek to the Smoke alone, surviving harrowing near-death experiences riding rapids, free-falling into chasms, and crossing broken bridges. Tally must rely on her wits and instincts; back home people bungee jump for a cheap thrill—in the wild, the stakes are life and death.

Furthermore, when Tally experiences the Smoke first-hand, she learns an entirely new way of life that changes her mind forever about the value of having life handed to you on a silver platter by your government as a Pretty, and making your way on your own. She meets David, who shows her she’s beautiful, flaws and all, and learns an important secret—the Pretty surgeries don’t just change a person’s face, they change a person’s mind. The government creates brain lesions in people’s brains during surgery to make them docile and acquiescent citizens. This is why, Tally learns, everyone back home seems to be naïve and meek, including her parents.

The climax of the novel occurs when Tally decides to abandon her mission to betray the Smoke and her friend Shay, which inadvertently signals Dr. Cable and her team by throwing the locket tracker they gave her in the fire. Tally does the “right” thing but to the opposite effect. The Smoke is destroyed, and its inhabitants captured, including David’s parents Maddy and Az, and Shay. Tally realizes she must rescue them or feel guilty forever.

The falling action of the plot follows Tally’s return home, armed with new knowledge—not only about the sinister, totalitarian nature of her society and its standardizing of beauty but of herself and her abilities, which give her the inner peace and confidence she was so yearning for. Tally saves the people of Smoke from Dr. Cable, but her victory is short-lived: David’s father, Az, dies, and her friend, Shay, has been turned into a Pretty. Tally is too late to save them.

The plot resolves with one last major, life-altering decision that seals Tally’s fate. To test an experimental drug that has the potential to reverse the brain damage the government inflicts on Pretties’ brains during surgery, Tally volunteers to undergo surgery so she can be a willing test subject. In an ironic and symbolic gesture, she has Shay handwrite her note of consent before the surgery to make sure she doesn’t back out after her brain is changed. Tally learns the value of repentance, and true self-sacrifice, as well as the true nature of beauty, achieved by selfless acts, in making this one last act to save her friend and hopefully the world.