San Diego defense attorney Paul Madriani is still reeling from the trauma of a near nuclear explosion he helped avert at the naval base in Coronado. Threatened by federal authorities to keep quiet about the close call in California, Madriani is now faced with a new problem in the steely-eyed and alluring Joselyn Cole, a weapons control expert, who believes he has to go public with what he knows if they have any hope of stopping a similar event in the future.

But Madriani has been linked to the murder of a Washington, DC, political staffer, and authorities believe a shadowy figure called Liquida—a hired assassin known as "the Mexicutioner"—may be responsible. And this man, as the last survivor of the attack in San Diego, might be driven by a bizarre, horrifying, star-crossed vendetta and might now be looking for Madriani himself. What Madriani and Cole begin to fear is that this madman has joined forces with a demented former radical known as the Old Weatherman, who intends to pull the city—and the country—into a vortex of terror before Madriani and Cole can find answers to the enigma that is "the rule of nine."