Frank entra em alerta vermelho com uma ameaça iminente a Nova York após um ataque terrorista no Oriente Médio.

Danny e Baez investigam um possível assassino em série que envia mensagens assustadoras para Danny. Ao mesmo tempo, Erin brinca com a ideia de tentar virar juíza. Já Frank enfrenta problemas quando a candidata à prefeitura, Katherine Tucker, o acusa de investigar secretamente seu marido. Para completar, Eddie encontra seu pai quando este vai parar no hospital.

O repórter Lorenzo Colt vira alvo enquanto usava a roupa da polícia em uma ronda na qual acompanhava Jamie e Eddie. Assim, Frank coloca Danny e Baez na caça ao atirador, que pode estar à caça de outros membros da força. Para completar, Garrett contempla a opção de aceitar outro emprego.

Um chefão da máfia enfrenta acusações por um velho assassinato, mas o caso não é tão simples de se concluir, já que um álibi inesperado surge — trazido por alguém que era informante de Erin. Enquanto isso, Frank bate de frente com o comissário de Departamento de Incêndio de Nova York.

Danny ajuda a ir atrás de dois condenados fugitivos, já que ele ajudou a aprisionar erroneamente um deles. Enquanto isso, Gormley critica um plano submetido por um sargento que pode estar tendo um caso com a esposa de Sid.

When Jamie is caught on camera committing what could be construed as police brutality at an anti-policy demonstration, Frank is forced to turn the case over to Internal Affairs. Also, Danny and Baez investigate a rape case involving a civil rights attorney who claims the charges were drummed up in retaliation for the investigation into Jaime.

Danny and Baez investigate the theft of the only remaining Mustang that Steve McQueen drove in the film “Bullitt,” owned by Owen Cairo. Also, Erin is at odds with Frank when she is forced to side with her office after the acting District Attorney orders that a slew of cops be arrested for fixing traffic tickets for their friends.

When Danny and his family are threatened by Thomas Wilder, a serial killer Danny has not been able to apprehend, Linda’s concern intensifies over her husband’s job as well as the state of their marriage. Also, Jamie challenges his superior officer, Sgt. William Mulvey, during a hostage situation.

Danny is interrogated by the District Attorney’s investigator when his ex-partner is accused of planting evidence in order to wrap up a homicide case. Also, when radical anti-government activists threaten to publicly burn an American flag, Frank grapples with the limits of free speech.

When Frank’s first partner announces plans to publish a book filled with stories of their early days on the force, Frank worries about his personal stories being made public. Also, when Jamie and Eddie catch a call about a nearby officer needing assistance, the choices they each make will affect their future in the department and their relationship.

When a local mobster is gunned down in his car, Danny and Baez try to get information from the mob’s low-level errand boy they find tied up in the trunk before the gang retaliates. Also, an NYPD officer asks for a new shield number to honor her late father, but Frank is conflicted as it’s the same number as his deceased son, Joe.

A respected, recently retired NYPD lieutenant is accused of shooting potential muggers on the subway; Baez and Danny try to arrest a drug dealer responsible for a murder Baez witnessed as a child.Source: CBS

Several women take the credit for murdering the man they worked for. Frank and his priest fall out over the best way how to deal with a boy who has been stealing from the church.

Erin finds it hard to deal with guilt after a man she set free is suspected of killing a policeman. Frank and Mayor Poole clash over Frank's reappointment as commissioner.

Linda needs Danny and Baez's help after a co-worker has difficulties with an angry ex. Erin's former mentor has been giving out unfair sentences following the death of his wife.

Jamie and Danny disagree about how to handle a reckless NYPD rookie, Marcus, who is the son of Danny’s friend. Also, when Erin’s investigator, Anthony, gets roped into a bad investment by his cousin, she offers to look into it.

Frank and Danny work together to help Nick Constantine (Michael Nouri), a rehabilitated ex-con who Frank put away years ago, when Constantine becomes involved in the murder of an old enemy. Also, as Erin prepares for a murder trial, she learns the prosecutor who previously handled the case is withholding the location of the alleged killer so she can interview him on her popular podcast.

While hunting for a robbery crew on a wild crime spree, Danny and Baez partner with Detective Jimmy Mosley, a detective from another precinct who broke Baez’s heart years ago. Also, when an officer who was acquitted on charges of killing a young boy is up for a promotion, Frank grapples with the decision of moving him up the ladder and risking public outrage.

When serial killer Thomas Wilder attaches a message to his latest victim that taunts Danny, their deadly game of cat and mouse becomes personal for Danny.

When a key eyewitness in a murder trial flees out of fear of retaliation, Erin and Anthony spearhead their own two-person manhunt to find him and convince him to testify. Also, Garrett tries to convince Frank to attend the Police Union party, and Danny and Baez take a closer look at a suspicious convenience store robbery.

Frank, the Mayor, Erin and the DA’s office contend with public outrage after a grand jury doesn’t indict an NYPD officer for the controversial shooting of a teenager that was caught on video.