Exodus 9 - In the Grips of Silent Terror, #4

Special Agents Samuels and Ricci continue their pursuit of those responsible for the largest-ever terrorist attack in the United States. The FBI Assistant Director has arrived in New York City from Washington, and he is demanding answers, and fast. The investigation is moving forward slowly, and the risk of another smallpox release has the team working around the clock. Washington wants to take over the investigation if the New York Field Office can't solve the case soon. The two agents uncover a link to a right-wing group called Exodus 9 and to a man Samuels killed during the raids on Mafia families.
They've made progress, but how many more people will die before all the pieces fall into place.