A special agent of the FBI, a case officer of the CIA, and a general in the U.S. Army have all taken the same oath--"to support and defend the Constitution." But when a bus blows up in Brooklyn and campaign of terror begins to make its bloody mark on the streets of New York City, the men and women who have sworn to protect the country must now reckon with the many implications of their oath. Anthony "Hub" Hubbard, the head of the Joint FBI/NYPD Terrorism Task Force, is the man charged with keeping the city safe from an array of threats that seem to grow more terrifying with every headline. Elise Kraft is a CIA operative, now undercover, with important sources in the Arab-American community and ambiguous ties to the suspects. Her agenda, like that of her government's foreign policy, is more complex than Hub's. And yet these two are forced to work together, forging an uneasy alliance, as the incidents of terror threaten to paralyze the city under siege.