Eddie and Jamie deal with a domestic violence case associated with an investigation led by Danny and Baez.

Frank announces he will not endorse Erin's run for district attorney; Danny and Baez investigate a bloody crime scene at a hotel; Jamie begins a new job as a field intelligence sergeant that requires him to keep secrets from his family.

Danny and Baez investigate after a vicious attack leaves their mutual friend hospitalized; Frank and the team debate the appropriate memorial protocol for a former police commissioner with a questionable professional legacy.

Danny and Baez investigate a series of violent robberies targeting luxury timepieces; Erin is conflicted about criminally charging a potentially innocent man; Frank is forced to reopen a case in which the officer involved was acquitted.

Frank launches an investigation after the Reagan family is harassed; Danny and Baez form an unlikely partnership with an informant in order to prevent a murder; Eddie lands in hot water after she defies a direct order.

Danny and Jamie clash over a gang-related shooting; Erin and Anthony search for answers when a lawyer in their office jeopardizes a case involving Erin's nephew; Frank grows concerned when he's not invited to speak at a policing forum.

Erin and Anthony clash when Anthony's daughter is the sole eyewitness to a fatal shooting; Frank wants to punish an off-duty cop for his inaction during an armed robbery; Danny and Baez investigate a violent mugging.

Danny crosses paths with a criminal from a previous case when he investigates a gang attack with a shocking motive; Frank and Mayor Chase butt heads over an off-duty cop who goes too far making a political statement.

Frank and Joe contend with a grievous insult to the memory of Joe's father; Erin and Henry work together to bust a scammer targeting the elderly; Eddie's captain takes suspicious interest in her efforts to locate a stolen puppy.

Jamie and his intel team officer infiltrate a high-tech car smuggling ring; Frank faces off against the city's transit chief over a program that is causing officer injuries on the job; Eddie asks Danny to help her bust a cop impersonator.

Danny and Baez's investigation into the death of a chess hustler is complicated by interference from the victim's son; Jamie tries to make amends with a man he regrets putting away as a young officer.

Danny reunites with childhood friend and a former criminal Mickey Patrick, who comes to him for help finding his missing fiancee; Anthony surprises Erin with one last stakeout before her run for district attorney.

Danny and Baez race against the clock to catch a serial killer targeting young women; Erin and Eddie clash when Eddie intervenes in a murder case and Erin's personal life; Frank must decide how to discipline his grandson.

The return of Rachel Witten, Eddie's former partner turned social worker tests her loyalties and conflicts Frank when Rachel brings an accusation of excessive force against an officer.

Danny partners with Texas Ranger Waylon Gates to deliver an infamous drug cartel boss to arraignment, but the mission becomes complicated when the criminal threatens to harm the Reagans; Erin takes on a highly contentious assault case.

Jamie learns that Eddie's close friend Tracey may be using the restaurant she owns as a drug front; Erin is accused of causing the suicide of a former colleague; Danny and Baez are faced with various descriptions of the same suspect.

Frank clashes with the team when one of the members becomes the focus of a departmental investigation; Jamie and Danny team up to investigate a series of carjackings involving one of Danny's criminal informants.

Frank clashes with Mayor Chase when an influx of immigrants arrives in the city. Danny and Baez investigate a case of grand larceny tied to feuding crime families.

Jamie partners with the FDNY to find the arsonist responsible for a massive fire at an NYPD evidence storage facility; Eddie asks Frank to put her on modified duty following her divisive arrest of an anti-cop protestor at a rally.

Frank worries his longtime friend is hiding his true reason for returning to the city; Baez and her daughter are targeted by a criminal Baez once put away; Anthony is sucked into the inner workings of an underground crime ring.

Danny and Baez team up with Danny's old partner to find a copycat killer emulating a criminal's murders from a previous case; Frank and Mayor Chase battle over how best to handle the city's rising homeless population.