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.

An inebriated Vince Gotelli is arrested after "hijacking" a city bus and having it wrecked. Fancy meets with the bus driver's boss to work out an arrangement about their investigation and suggests that Gotelli take some medical treatment. But it takes a forced intervention by Martinez, Medavoy, and Russell to convince Gotelli to get medical and psychiatric help in which Gotelli decides to throw in his badge for good. Meanwhile, Simone's continuing help with the FBI makes his life miserable when the men from Internal Affairs investigate him for the government license plate number on Salvo's car that he ran and is frustrated when he cannot tell them, not even Sipowicz, about what he's doing. Elsewhere, Sipowicz and Simone investigate the beating and murder of a woman in her apartment and deal with the emotionally sensate superintendent of the building whom they think he knows more than he's telling them.