Danny arrives at a scene where a Mrs. Davis is talking to a uniform. She tells Danny her soon-to-be-ex came around screaming and refusing to leave. Her young son is upset that she called the cops. A CPS investigator is on scene -- Henry.
Eddie and her partner pull over a vehicle with expired plates. Eddie's partner claims to find something in the car and says he's searching the vehicle. He finds a gun under the front seat. The driver is arrested for a recent shooting.
Frank talks to his staff about how the FDNY commissioner ended up getting arrested during a noise complaint. Gormley blames the FDNY.
The new Mayor wants Erin to run for Manhattan DA. He doesn't like her boss' idea that criminals and victims have equal rights.
Henry is working with ACS because they have too high caseloads. Henry thinks the husband in this case is a decent guy who got hooked on pain meds. Danny doesn't think t hat's a decent guy. He works at a drug rehab. Danny wants to drop Henry off before he investigates but Henry says he is working this case too.
Erin is not paying any attention to Anthony's comments about a case. She tells him about the offer. ANthony thinks she should run.
Jamie congratulates Eddie and her partner on the arrest. Eddie seems upset but says nothing is wrong when Jamie asks.
The FDNY guy is angry at Frank, who blames the NYPD and says the NYPD harasses the FDNY all the time. He gives the FDNY guy a summons.
Henry talks to the suspect who says that he was thrown off by the divorce papers. He doesn't want to live his son. Henry thinks that Danny should skip telling the parole officer about this. Danny says fine, but don't do it again.
Jamie is concerned about the arrest report. The suspect had no drugs on him except the vial in the back? Is she sure Troy found it in the car? Eddie thinks he did. Jamie says he might have to call IAB. Eddie says the perp will walk and she will be investigated, but Jamie says he can't look the other way.
Danny is called to the Davis residence again. The husband is back, getting violent because the mother got a job offer n LA. Henry doesn't want the guy arrested. Danny arrests him anyway.
The husband says he needed to talk to Karen. Danny says you get a lawyer and work out custody, you don't do this. He's irritated that Henry got the guy a desk appearance ticket.
Abigail finds out that Zerely, the cop that arrested the FDNY commissioner, got into another fight with the FDNY in the past and has been ejected for fighting from three games when playing hockey with the FDNY.
Erin talks to the Mayor's assistant. She says she hasn't made a decision, so why is she here? He says Chase thinks she would make a great DA and he agrees. Erin asks for advice. He thinks she would be buying into something new and unknown if she ran for DA.
Eddie is upset that she got a call from IAB. Jamie tells her just tell the truth. She doesn't know the evidence was planted. She has her partner's back. She says Phelps is a murderer and Troy is a good guy. Jamie says Tory is worse because he took an oath.
Danny catches the husband at Karen's again. He says he got a text asking to meet. Henry shows up and says he checked with Karen and she didn't text her husband but her husband got a text. He says if Danny arrests the guy he's complicit in a setup. Danny tells the guy to go home and not come back.
The FDNY and NYPD has had another fight. Frank says that no one knows who the FDNY commissioner is so he doesn't blame him for being mad. He's had enough of this rivalry. He wants Zeleny to take one for the team.
Eddie is angry about the IAB guy. She says that if Troy loses his shield everyone will think she's a rat.
Erin comes to see Frank. He asks if she's all right. She says yeah, work stuff. Frank knows she is running for DA. She wanted to come to him right away but thought she should make the decision on her own. She says she wanted this her whole life. Plus it's time for a female DA in Manhattan. Frank thinks she would be a great DA but is concerned about the heightened scrutiny the family will be under.
They discuss it at Sunday dinner. Eddie worries about whether her dad being a felon will be a problem. Erin says it won't, nor will Jamie's water dousing misadventure. Danny isn't sure about his record but Frank isn't worried. Sean wonders if a fake ID is a problem. Erin teases Danny about having one that said Marian Morrison. Danny says that is John Wayne's real name. Sean doesn't know who that is.
Henry isn't happy with Danny. Danny thinks Henry has become a bleeding heart. Henry says the father going to jail will hurt his son. Danny says he became a cop because of Henry's stories about cops doing whatever they had to do. Danny says he's riding solo on this case from now on. Henry says he will be too.
Mrs. Davis comes to see Danny. Her husband has kidnapped her son from soccer practice.
Henry is hanging around. Danny says it wouldn't have happened if the guy was locked up. Henry says it wouldn't happen if the guy wasn't treated like a perp all the time. Henry knows where the guy is.
The mayor's assistant asks Erin a bunch of questions about potential skeletons. He says if she's looking at the scrutiny as an excuse not to run it's not a good excuse.
Jamie talks to Troy. He says he knows seasoned cops sometimes throw procedure out the window. Troy says he didn't do anything wrong. He says Phelps is a murderer. Jamie says that doesn't justify what he did. He suggests Troy retire today so he doesn't lose his pension. Troy says okay.
Henry and Danny find the father and son at a hockey game. Danny decides to let them watch the game while he watches. Henry says sometimes there's no bad guy
Jamie comes home. Eddie says Troy put in his papers and that gets her off the hook. She wonders how he did it. Jamie says he put her in the fire so he had to pull her back out.
Mayor Chase shows up and tells Erin he doesn't think the current DA likes him. He shows her a photo of his famlly. He says he wants her to know his interest in her is just collegial. She believes that.
Chase says he is looking at other candidates but he likes Erin for this position. For people he believes in, he throws obstacles in the way.
The FDNY commissioner is celebrating his birthday with his squad when Frank and Gormley show up. Frank makes Zerely apologize to him and says the DA is dropping the charges. Gormley gives him a birthday card with a courtesy card with Frank's number.