The protagonist is Lauren Olamina, an African American girl who is fifteen years old when the novel begins. She lives in Robledo, about twenty miles from Los Angeles, which has become a walled enclave only partially protected from the rampant lawlessness and desperate poverty that exists beyond the walls of the neighborhood. When the enclave is completely destroyed by bands of arsonists and thieves, Lauren is one of the few survivors. She heads north, on foot, with a couple of companions in a perilous search for a better life.

Butler's disturbing dystopia, written in the form of Lauren's diary entries, is at once an adventure story, a coming-of-age story, and a thought-provoking exploration of some negative trends in American society that have become more pronounced in the decade that has elapsed since the novel was written.