The time is 2025. The place is California, where small walled communities must protect themselves from hordes of desperate scavengers and a roaming band of people addicted to a drug that activates an orgasmic desire to burn, rape and murder. When one small community is overrun, Lauren Olamina, an eighteen-year-old black woman with the hereditary trait of 'hyperempathy' - which causes her to feel others' pain as her own - sets off on foot along the dangerous coastal highways, moving north into the unknown.