A SWAT team closes in on the house where a United States Senator is being held, and the tension rises as the bomb squad arrives. Frank Glass (the bomb squad chief) discovers a bomb in the basement and races to disarm it while a fierce shootout rages between officers and the hostage takers. Glass manages to neutralize the device, but he suspects it was a trap meant to mislead him. His instincts prove right when the real bomb detonates, and everyone inside the house is killed.
One year later in San Francisco, narcotics cops Ray Nettles and his partner Art “Fuzzy” Rice pursue a suspect on drug charges. Ray makes a fateful decision to let a pleading woman go, a choice that will haunt him as he confronts the consequences of his unresolved grief for his wife and son, who died in a car bombing. The duo stakes out a warehouse and, as night falls, a tense confrontation unfolds: Ray corners a suspect, but Fuzzy is shot by a ruthless leader, and the trio behind the operation scatters.
Clues begin to converge when Ray arrests the woman, Claire, who refuses to divulge information about the men behind the plot. She wears a peculiar bracelet that the bomb squad examines, revealing detonation cord and Semtex. The investigation gathers pace as a distinctive cigarette and a matchbook from a jazz club connect a new thread to the case. At the club, the team eliminates one bomber and presses Claire for insights about the masterminds, who are identified as Swan and Vershbow. Claire insists she will be killed for talking and agrees to cooperate, but her alliance wavers as danger closes in.
Swan, a calculating mastermind, plans a grand bombing at the police station, though Vershbow has his own agenda and forces Swan to hand over the bomb under threat. The police corner them, and it seems Glass helps avert a detonation—only for Swan to trigger several more bombs using a pay phone. The threat expands as Swan coordinates a much larger assault with a crew led by Vincent Cruichshank, escalating the citywide danger and forcing Ray to improvise under pressure.
Propelled by a mix of pressure and desperation, Ray convinces the police to release Claire so she can be tracked and corner Swan. Claire meets Swan and disables a tracking device, choosing to work with him again as they discuss their looming “masterpiece.” She heads to a phone booth to activate the bombs, detonating a car bomb in Swan’s car, leaving everyone shaken and unsure of who truly holds the power.
As the pursuit unfolds, Ray and Glass realize they may both be risking their lives for a larger cause. They race toward City Hall, each taking a different route—Ray to the basement and Glass to the roof. Ray, guided by Glass’s voice over the radio, must disarm a bomb while trying to stay calm and honor his late family. The device in the basement turns out to be a decoy; the real threat is on the roof, where Glass manages to disarm the final bomb, bringing the crisis to a close and restoring a fragile sense of safety to the city.
