Main character Ursula Van Urden is introduced arriving in Middle City, a fictional American metropolis built around a volcano.

Javier, a manic optimist, takes Ursula on rollerblading and party-crashing expeditions, predicting a new megatrend he calls the "Light Age," a "renaissance of self-creation," which he believes will coincide with the defeat of irony.

By contrast, Chas, a cynical ex-philosophy professor, takes her to skulk in supermarkets and spy on customers, and introduces her to the concept of "paradessence," the "broken soul" at the center of every product, consisting of two opposing desires that it will promise to satisfy simultaneously.

As Ivy resumes her modeling activities, Ursula's trendspotting work focuses on a homeless girl who lives in a city park, makes her own clothing, and hunts pigeons for food.

This eponymous "savage girl" forms the basis of a marketing campaign for a new product, "Diet Water," and serves as a harbinger for Chas and Javier alike, of the new age to come.