The fourth book in Westerfeld's Uglies series, and we're right back at the beginning. The first book featured Tally Youngblood, who wanted to be made pretty at all costs. She then falls in with a group of daredevils who want to bring down the regime and remain ugly, decides that maybe there way is the One True Way, then betrays them all and we're off toward Book 2. 
 Extras is the Asian reboot. Aya Fuse wants fame, her culture's unit of currency, and she plans to get it by breaking a story about the elite group of daredevil girls who actively try to stay out of the limelight. Aya follows them, wins their trust, and becomes one of the group, planning to betray them all along--but then her scoop gets bigger. Sound familiar? This time we're saving the world instead of preserving a culture, but the basic story structure is the same, right down to the complicated love interest with different values. 
 Westerfeld's invented slang (things can be bubbly or icy; fame-bloggers "kick" their stories) feels far less organic than it did when the series began, as if slang has not progressed in the 5 years since Tally first appeared (though technology has changed almost daily). Most annoying is his refusal to use adjectives relating to emotions--a situation is nervous-making or happy-making; a boneheaded move is brain-missing. 
 I think this is the final volume in what was once a trilogy. Knowledge of the earlier books is helpful for context, but eliminates most surprises. It's better than Specials, but I find myself wishing this quartet had been a duo.