Plot
Colin Laney is living in hiding in Tokyo's Shinjuku district, weakened by earlier 5-SB drug trials that have left him physically ruined but able to perceive "nodal points", moments when events are about to shift decisively. Watching the movements of public-relations magnate Cody Harwood, Laney concludes that Harwood has also recognized an approaching nodal point and intends to exploit it. Believing that the next such convergence will occur in San Francisco around the Bay Bridge settlement, Laney asks Shinya Yamazaki to find Berry Rydell and send him there in his place because he is too ill to travel.
Rydell is working security at a Lucky Dragon convenience store in Los Angeles when Yamazaki finds him and relays Laney's request. He also gives Rydell a projector unit containing Rei Toei, the virtual idol introduced in Idoru. Laney offers little explanation beyond insisting that Rydell take the unit to San Francisco and keep moving. Trusting Laney's judgment, Rydell leaves Los Angeles and heads north.
Chevette Washington is also returning to San Francisco. Having left her abusive boyfriend Carson, she goes back to the Bridge, where she had once lived, hoping to disappear among its residents. Her friend Tessa, an Australian film student making a documentary about marginal urban communities, drives her there and continues filming the Bridge and the people around it. Carson follows Chevette, determined to recover control over her.
Harwood sends the assassin Konrad west as part of the same operation. Konrad closes in on Rydell but, when he has the chance, does not kill him. Instead, he turns on the other men pursuing Rydell and begins moving alongside him rather than against him. On the Bridge, Fontaine is caring for a mute boy named Silencio, who is obsessed with watches and seems uncannily able to find them. Silencio becomes fixated on one particular watch, and Fontaine realizes that the boy's obsession is connected to larger events.
After Rydell reaches San Francisco, Harwood's men attack him directly. Konrad intervenes and keeps him alive. Rydell and Konrad then encounter Chevette, who takes them to Fontaine's watch shop on the Bridge. Fontaine and Silencio shelter them there, bringing the main strands of the pursuit together in one place. Realizing that the people and objects he wants have converged on the Bridge, Harwood escalates the conflict. When his operatives fail to resolve the situation, he orders the Bridge set on fire.
Inside Fontaine's shop, the Rei Toei projector ceases to be mere cargo. Konrad links the device to Silencio's eyephones, allowing Rei Toei to guide the boy as he follows the watch through cyberspace. Because the watch is tied to Harwood, Silencio is able to trace it back to Harwood's hidden position. From Tokyo, Laney joins the effort remotely from his shelter in Shinjuku, while allies in the Walled City help interpret what Silencio is finding. As the fire spreads across the Bridge, Laney and his allies use Silencio's tracking and Rei Toei's guidance to close in on Harwood.
The fire drives residents out across the Bridge and into the surrounding streets. In the confusion, Rydell becomes separated from the others and struggles through smoke and wreckage, at one point encountering the country singer Buell Creedmore as both men try to escape the flames. Carson's attempt to reassert control over Chevette collapses amid the chaos, and she finally escapes him. Konrad continues acting against Harwood rather than serving him, carrying his break with his employer through the climax.
The nodal point resolves through Rei Toei rather than through Harwood's design. No longer confined to the projector unit, she uses the Lucky Dragon network and the technological systems around the Bridge to cross into physical form. Harwood fails to master the event he had tried to control. Instead, Laney's warning proves correct: the decisive change occurs in San Francisco, Harwood's plans are broken, and Rei Toei emerges into the world in a new way. Rydell and Chevette survive, Carson no longer controls Chevette's life, and the Bridge endures the fire though badly damaged. Laney remains in Tokyo, dying, having correctly foreseen where the shift would occur.