A NYPD whistle-blower claims there's been abuse of power within the organization, so Frank must investigate whether this is true. Meanwhile, Danny and Baez are suspicious of a car accident involving a pedestrian and think it may have been intentional.

Jamie and Eddie suspect foul play when they respond to a distress call from a woman having an allergic reaction to her lifesaving medication, and learn that her husband is an EMT assigned to take her call, but didn't respond. Also, Erin learns that a man she convicted years earlier might be innocent of the crime, and Frank handles a PR crisis in his department when an exposé on Garrett Moore is published.

Frank receives an order from the mayor to attend a parade honoring a man who served time for conspiring in an attack against the police. Meanwhile, Danny investigates the return of a teen who suspiciously disappeared 13 years ago; and Jamie and Eddie help a young woman they believe is being exploited by a congressman.

When a journalist disappears while working on an exposé about an innocent man serving time for murder, Danny and Baez hope that reexamining the original case will help find her. Also, Frank reluctantly speaks out against an initiative led by Erin's office to consider drug abuse as a disease first, and a crime second.

After Anthony is shot while interviewing a witness for an upcoming murder trial, Erin enlists Anthony's archenemy, Danny, to find out who was responsible. Jamie and Eddie get in the middle of a standoff between a police lieutenant and a developmentally disabled man posing as an officer and Nicky prepares to take the police exam.

When a video surfaces of officers partaking in a clear case of entrapment, Frank focuses on finding the cop who leaked the video. Eddie retaliates against a co-worker who is pranking Jamie. Danny and Baez investigate the murder of a tabloid writer who worked in the hip-hop scene. Erin gives a high-profile case to a young ADA under her tutelage.

Frank's longtime friend Lenny (Treat Williams) reveals to him that an upcoming exposé will air some of the NYPD's dirty laundry. Also, Erin must decide how to charge a doctor whose experimental treatments led to the death of his terminally ill daughter; Danny and Baez investigate the mysterious overdose of a promising artist; and Jamie follows a lead about a corrupt officer in his precinct.

Frank works to vindicate Detective Douglas McKenzie, a detective accused of using excessive force. Also, Danny and Baez track down the killer responsible for the death of a rapper’s bodyguard. Jamie is skeptical about a relationship between Espinoza and a new rookie officer, Sarah Brooks; and Eddie goes undercover to help Erin investigate a mysterious cult.

After an EMT is shot and killed, Danny and Baez work to determine who is behind a chain of ambulance robberies; Frank defends New York's homeless community after the mayor puts a new law in place; Eddie offers to help Jamie pay off his student loans.

Erin and Anthony trust a sociopath who claims he has evidence to convict a murderer; Frank faces backlash from his department when he suspends an officer for violent behavior; Danny and Baez try to arrest a notorious gangster.

Danny and Baez are faced with tracking down a drug dealer after two young models are found dead from an overdose. Also, Eddie and Jamie team up to determine who the mastermind is behind a robbery.

Frank struggles after Joe Hill's lineage as a Reagan is revealed; Erin and Anthony receive gift-wrapped evidence; Danny's opposition to authority clashes with Jamie's adherence to the rules, as both brothers work to solve a murder.

Frank asks Erin to liaise between him and NY Governor Mendez regarding policy reform he privately backs, but can’t publicly support, because it goes against police rank and file. Danny and Baez become enmeshed in the world of competitive gaming when a high-profile video game streamer is murdered, and Eddie and Witten suspect a live-in nanny is being abused after she approaches them on the street for help.

Shockwaves ripple through the Reagan family when Danny discovers that their newest family member, Joe Hill (Will Hochman), is working undercover for the ATF to bring down a gunrunning organization.

The Reagans band together to prevent Joe Hill from being killed in the line of duty like his father when they fear Joe’s cover has been blown within the gunrunning outfit he’s helping the ATF bring down.

Frank must decide between remaining police commissioner and pursuing a new professional chapter when his old friend presents him with an exciting job offer. Danny and Baez investigate the murder of a restaurant delivery man.

Danny partners with Anthony to solve a double homicide when Anthony's shady cousin proves to have gang ties to the crime; the boundary between Eddie and Jamie's work and personal relationship becomes strained.

A local celebrity asks Frank to make an exception to the NYPD age limit; an encounter with an old rival leads Erin to look into an alleged wrongful conviction; Jamie is torn over whether to report a sergeant; Danny and Baez look for an abducted kid.

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 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.

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 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.

Frank grapples with the personal loss of his best friend and how best to help Tess Ross, the daughter of his best friend, when she lands in jail. Also, Jaime and his nephew, Joe Hill, race against the clock to reunite a trafficking victim with her sister; and Danny and Erin clash when she goes behind Danny's back to use his criminal informant in an investigation.