Denizens of Lux have come to call it "The City" and treat it as a sentient force. Three factions vie for control of the city: the Organo, a strictly professional conglomerate with ties to the criminal underworld in the prosthetics business; the Union, a fanatical populist group interfering with Organo's affairs; and Racan, a marauding group of Texhnolyzed youths.

Lain—driven by the abrupt suicide of a classmate—logs on to the Wired and promptly loses herself in a twisted mass of hallucinations, memories, and interconnected-psyches.