Henry Dorsett Case is a low-level hustler in the dystopian underworld of Chiba City, Japan. Once a talented computer hacker, Case was caught stealing from his employer. As punishment for his theft, Case's central nervous system was damaged with a mycotoxin, leaving him unable to use his brain-computer interface to access the global computer network in cyberspace. Unemployable, addicted to drugs, and suicidal, Case desperately searches the Chiba "black clinics" for a miracle cure. Case is saved by Molly Millions, an augmented "street samurai" and mercenary for a shadowy ex-military officer named Armitage, who offers to cure Case in exchange for his services as a hacker.