A female private investigator is assaulted by some cops. She files charges and Nick is about to let the case push through when the police provide them with an alibi. So he dismisses the case and the woman is not happy. Nick proceeds to pursue them and the woman follows them too and discovers Nick. Later one of the men is killed and Nick wonders if she did it.
When a man is picked up by a woman and taken to a motel room, he passes out. When he wakes up, he discovers that his kidney's been removed. When the woman is arrested and brought in front of Marshall, he has no choice but to release her. So he and the team try to find out who is behind this.
A man who committed a crime is arrested and Nick presides at his trial. When on the stand the man claims that he did it because his therapist made him do it. Nick learns that she's a sex therapist and is using her patients need for her "help" to make them do things. Nick, Moon and Gibbs go to her under the guise of needing help. And when she kills someone Nick fears that she's going to be more dangerous.
Nick has his sights on a lawyer who seduces wealthy men into giving her their fortune then killing them. Kelly is hired by a man to locate his wife, when in reality he married her for her money and then killed her. When Kelly learns what he is up to, he tells Nick. They decide to use him to get the lawyer.
A woman is killing judges. And she has her sights on NIck. An FBI agent who knew one of the murdered judges visits Nick and tells him that she could be after him because it seems that all of the judges killed were advocates of following the letter of the law.