Frank goes on high alert when a threat to New York City may be imminent following a terrorist attack in the Middle East
Danny and Baez investigate a possible serial killer who sends a chilling message to Danny, and Erin toys with the idea of applying for a judgeship. Also, Frank is in a bind when mayoral candidate Katherine Tucker accuses him of secretly investigating her husband, and Eddie faces her estranged father when he winds up in the hospital
When newspaper reporter Lorenzo Colt is targeted while wearing NYPD gear on a ride-along with Jamie and Eddie, Frank puts Danny and Baez on the hunt for the shooter who may be out for other members on the force. Also, Garrett contemplates taking another job
Erin's attempt to convict a slippery mob boss for an old murder is muddled when her former informant, Vincent, leaves witness protection to provide his old boss with an alibi. Also, Frank finds himself in a departmental war with Commissioner of the New York City Fire Department, Stan Rourke
When a homicide case ends in a hung jury, Erin is forced to take over the case from her colleague, ADA Kelly Blake, and with the help of DA investigator Anthony Abetemarco, find a missing witness. Also, Jamie and Eddie go undercover as an elderly couple to catch a gang that is terrorizing a neighborhood.
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.
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.
Frank and Danny try attempt to help a rehabilitated former con after he becomes involved in the murder of an old enemy.
Whilst looking for a gang of robbers, Baez works with a detective with whom she shares a romantic past.
An investigation ends up becoming personal for Danny after a serial killer attaches a message for him on his latest victim.
After a witness in a murder trial disappears because of fear of retaliation, Erin and Anthony need to find him and convince him to still testify.
Frank, the mayor, Erin and the DA's office have to try and deal with some public outrage after a grand jury fails to indict an NYPD officer for the shooting of a teen.