A professional hit at a law firm leads Willows to suspect that the company has hired a team of assassins to eliminate anyone who knows of their activities.
A spoiled heiress is found dead in her bathtub during her own party and there's no shortage of suspects; Horatio tells Delko that he and Marisol plan to wed as soon as possible.
Sydney goes under cover as a social worker, and Vaughn, as a lascivious priest, in their search for the new bioweapon; Nadia turns to reluctant Jack to learn the truth about her mother, Irina.
With Tony in custody, Jack leads his interrogation, but is shocked when a code word Tony whispers in his ear leads to old friends and a plot much deeper than anyone in the FBI anticipated.
Following the President's refusal to withdraw her troops, Dubaku launches a terror attack on a high-profile American. Meanwhile, Walker is recruited by Jack and Tony.