At the end of summer, Shay and Tally decide to do one more prank: with the help of a bungee jacket, they frighten a bunch of the new uglies by pretend fighting and throwing Shay off a high level inside the library.
The breakdown in ages becomes clearer here: up to 12, you're a littlie and live with your parents in the suburbs; from 12 to 16, you're ugly and live in the dorms; at 16, you turn pretty and go live in New Pretty Town.
(Gee, that's weird. Ages 12 to 16 almost exactly correspond with adolescence—a time when, hate to say it, a lot of kids do go through an awkward stage.)
Then they go swimming, where they get into a real fight about the whole pretty thing.
Tally thinks being turned pretty is a good thing and that the whole idea of prettiness is biologically determined.
Nuh-uh, says Shay. The pretty surgery makes everyone look alike and that they're just culturally programmed to enjoy the pretties.
Shay says she doesn't want to be pretty but Tally says that she has to grow up sometime. If they had Facebook in this future, this might be a moment when they un-Friend each other. But don't say that Westerfeld didn't warn you what was going to happen in this chapters, since it's titled "Fight."