Simone and Sipowicz collide in their squad car with a Romanian immigrant who has a woman locked in the trunk of his car and later, their investigation shows him to be a possible terrorist and holding a wealthy family prisoner with pipe bombs. Meanwhile, the serial killer, George Putnam is shot by an unknown sniper. Simone begins to investigate the father of the killer's last victim, Mr. Rudman, and another member of a victim's support group... who all appear to be part of a secret vigilante group. Medavoy talks to Dana about his relationship with Donna if he's losing interest in her, but the crafty Dana takes advantage of the situation to try to break them up by playing on his mental neurosis as the cause of Donna's lack of trust in Medavoy. Also, Martinez keeps asking Lesniak to go out on a date with him.

Simone makes contact with Ferdinand Hollie, an old informant, who wants to help him capture a pair of Colombian drug dealers who killed a young girl with their crossfire. But Hollie, a drug addict who is HIV-positive, has his own agenda to rob the Colombians. Meanwhile, Russell is paired with Sgt. Ray Kahlins, a "blowhard" from the federal anti-drug unit who is more interested in collecting overtime pay than catching a separate pair of drug dealers during a stake out. But Kahlins' brash tactics and disrespect for Simone and his informant Hollie, put both cases at risk. Also, Medavoy and Martinez investigate the murder of a Santería priest found in a local sewer and try to link a parole officer and a recent parolee to the crime.