Joe Hill is on a mission. He hears people inside and knocks softly on the door. The people say they'll be right there and start flushing copious amounts of drugs down the toilet. Joe realizes it and breaks in despite the other cop saying it's a knock warrant. He arrests some people, one of whom he seems to know.

Baez and Danny find a dead woman who was posed to look like a suicide, with a rosary and a note from the killer.

Eddie and Badillo arrive at the scene of a stabbing and a girl confesses. However, the girl won't talk to Erin because Eddie told her not to talk without a lawyer.

Joe and the other cop argue in front of Frank about whether Joe was wrong. The FBI guy says that Joe broke protocol. Sid takes Joe's side. The FBI guy accuses Frank of giving Joe special treatment. Frank shuts that down but privately tells Joe that he doesn't listen and always blames others for every problem.

Danny and Baez talk to the victim's boyfriend who says his girlfriend was not religious and he walked her home and left because he had a presentation. He wants them to find the guy who did this, as he did not kill her. He claims everyone loved her and won't answer more questions.

Erin confronts Eddie, who says she believes the perp. It turns out Jack is the defense attorney. Eddie called him. Erin is aggravated.

The Dream Team disagrees about Joe. Frank says Joe has a chip on his shoulder and he doesn't know what his problem is.

The ME says that Sarah was strangled. The rape kit is not processed yet. She was bound before death. They get another victim. It's a serial killer.

Jack wants to see Erin. She's upset he didn't give her a heads up. He says she broke up with him and now wants to dictate which cases he's taking?

The only thing the victims have in common is the rosary beads and that they are women in their early 20s. Danny gets a call. A reporter has got a letter from a guy taking responsibility for the murders.

Danny is annoyed that the reporter didn't take care not to contaminate the envelope. After exchanging words Danny starts over and asks to look at the photos.

Joe is here to see Frank. Joe is angry that he has been transferred. He says he followed the letter of the law. Frank says he didn't follow the chain of command properly. Joe accuses him of not wnating him to be limke his father and storms off. Frank says he has reflected on that and whatever this problem is, it's not that.

Erin doesn't want to hear from Eddie. Anthony tells Erin that Duarte did sexually harass and possibly rape his employees. Erin asks if there were witnesses, etc, which there weren't. She wants Anthony to find out where the weapon came from.

Eddie talks to Jack about the case. He should talk to Badillo directly about his thoughts. Eddie asks why he and Erin aren't together anymore. He explains they got married too young and were parents too early. Plus the family was very vocal and opinionated. However he blames himself for what happened. However he says Erin's priority is becoming DA and he doesn't fit into that equation. Eddie doesn't think he should walk away. He says back to the case.

A forensic psychologist comes to talk to Danny and Baez. He suggests the guy is smart, white, had a traumatic childhood, and a religious mother. He says the victims were young, female, and meticulous about their appearance. They were brunettes so his mother probably was. Dr. Walker thinks they should appeal to the public to give the guy attention. Danny doesn't like that idea. A partial print comes back belonging to a Martin Langley who runs a religious supply store.

Martin says he sells the rosaries and mails them to customers. He says he was with his mother in Great Neck. A lot of people have purchased the beads. He looks at his records and there was a guy who bought ten rosaries, but paid cash. In his 40s, glasses and suit, and was complaining he got a ticket for parking in a no standing zone. He also wanted the St. Benedict medal which is used during exorcisms.

Joe has to drop something off for Frank. Frank wants him to say hi.

Joe tells Frank he feels like he's competing with a ghost. Frank says that Joe Sr. would have been a great cop and great father and he died too soon. That is all. Joe wants to know who he is being compared against. Frank doesn't know.

Erin and Jack argue over the case. The co-workers say this was revenge. Jack says the jury will never convict. Erin takes the challenge.

Everyone is quiet at dinner. Erin is annoyed at Eddie. Erin thinks they shouldn't talk about this at family dinner. Jamie agrees. Danny says Eddie was playing matchmaker. Eddie says her intentions were pure. Erin doesn't believe that. Jamie thinks everything is influenced by past history.

In the kitchen, Eddie admits she likes the idea of Erin and Jack together. Jack makes her happy.

Baez and Danny run license plates. One belongs Io Dr. Walker.

The cops interrupt Walker's "Session" with nobody. They know he bought 10 sets of rosary beads. Danny finds locks of hair in the trash and arrests Walker.

Walker is humming while his lawyer says he is innocent. She says he's sick and therefore can't talk to them. She claims his mental illness is caused by being arrested. Walker bangs his head on the desk and is sent away. The attorney wants him evaluated. Danny thinks he is faking. The hairs in t he office don't match either victim.

Jack asks Erin how it went. Grand jury refused to indict. All that mattered was she was seen as a victim fighting back. Jack believes her. Erin still thinks this is pre-meditated murder but she doesn't have a case so he wins. Jack doesn't feel like a winner. Anthony shows up and says he found out Jennifer bought the murder weapon. It's too late.

Walker bangs his head against the wall and quotes the Bible. When he is alone with Danny he says he killed all of them but he is dragged away before he can tell Danny who else he killed.

Joe comes to the house. Henry is out with his friends from his days in the 3-5 so Joe is alone with Frank. They have bourbon together. It was his dad's favorite. Frank apologizes for being unfair. Joe says he learned a lot from the Chief. Frank says they all knew, loved, and lost Joe Sr. and Joe never knew him so of course he feels he is compared to his dad.

Frank shows Joe home movies of his father as a little boy, wearing Frank's cop hat. Joe Sr always copied what Frank did. He hated ties like Joe does.

Joe sees a shot of a teenage Joe Sr. with the rest of the kids. His father looks like him.