Colin Laney, sensitive to patterns of information like no one else on earth, currently resides in a cardboard box in Tokyo. His body shakes with fever dreams, but his mind roams free as always, and he knows something is about to happen. Not in Tokyo: he will not see this thing himself. Something is about to happen in San Francisco, and Laney needs a man on the ground there.
Rydell has no pressing reason not to go to San Francisco. Chevette isn't running toward Rydell, though of all her ex-boyfriends he's the only one she might want to run toward. But in any case she's running to San Francisco, to her old home on the Bridge, where people live who have no place else to go.
The mists of San Francisco make it easy to hide, if hiding is what you want, and even at the best of times reality there seems to shift. A gray man moves elegantly through the mists, leaving bodies in his wake, so that a tide of absences alerts Laney to his presence. A boy named Silencio does not speak, but flies through webs of cyber-information in search of one object that has seized his imagination. And Rei Toi, the Japanese Idoru, continues her study of all things human. She herself is not human, not quite, but she's working on it. And in the mists of San Francisco, at this rare moment in history, who is to say what is or is not impossible....