A computer virus that is manifested as a drug called Snow Crash that is transmitted visually from computer screens to unsuspecting users, frying their brains. Hiro Protagonist - that's the character's name - a computer hacker/samurai swordsman/pizza delivery driver who investigates and tries to stop the takeover of postmodern civilization. It sounds wild, but it is steeped in its own mythology and has become a cult favorite among the cyberpunk set.