Danny takes a case involving a drug cartel member he believes set his house on fire; Erin is given a promotion but finds herself in a challenging situation when both Danny and Jamie ask her for help with their investigation.
Gormley tries to locate a former NYPD detective he believes may be a threat to Frank's safety; Erin navigates office politics when she chooses to reopen a closed case; Jamie is transferred to a new precinct with a lot of problems.
Danny investigates a case involving a woman who shot her husband while she was drunk; Anthony defies Erin's orders to drop an assault case; Frank holds an emergency drill for his inner circle.
When New York City experiences a major blackout, police officers scramble to contain the resulting chaos; Frank uncovers some unpleasant truths about his department; Jamie and Eddie question the line between work and their relationship.
Danny and Baez investigate a murder attempt of a celebrated fertility doctor with a seemingly pristine reputation; Eddie must intervene in a Regan family matter involving Danny's boys; Erin helps Anthony find justice after a date goes wrong.
Jamie clashes with Eddie and her new partner when they fail to intervene in a dispute at a convenience store; Danny and Baez investigate the death of a college freshman at a fraternity party; a sergeant accuses the department of reverse racism.
The drug cartel hitman responsible for torching Danny's house resurfaces. Also, an attack on an officer in the line of duty directly impacts a member of Frank's team; Eddie reluctantly introduces Jamie to her mother, Lena; and Erin deals with the consequences of her new role as boss.
Erin and Frank clash over a new policy from the district attorney's office that undermines Frank's policies; Erin is at odds with Governor Mendez over questionable sex-trafficking laws; Danny risks his badge to protect a friend from losing his.
When a video surfaces of cops being harassed by a group of people at a housing complex, Frank orders a raid to round up anyone with an outstanding warrant, against Garrett's advice.
A video surfaces of officers partaking in a clear case of entrapment; Frank searches for the leaker; Eddie retaliates against a co-worker who is pranking Jamie; Danny and Baez investigate the murder of a tabloid writer.
Frank questions whether a run-in with community activists was an accident or a setup; Jamie strives to rely less on Frank's input to make decisions; Erin helps Anthony protect his daughter and ex-wife from a dangerous psychiatric patient.
After a former officer waits on Frank at a restaurant, he feels guilty about the circumstances surrounding why she was fired, and he tries to reinstate her.
A medium claims to know what happened to a woman who was found dead of an apparent suicide; Jamie and Eddie help a woman who bought cheap insulin online that nearly killed her son; Frank goes after a man he thinks is laundering money from a charity.
Danny goes against a direct order during a hostage negotiation; Nicky asks Erin for help when her friend is in jeopardy of losing his scholarship because of a crime he didn't commit; Frank helps a distraught officer who accidentally shot a girl.
While off duty, Danny encounters a gas station robbery in progress and is forced to use his weapon, leaving him shaken and his family and co-workers concerned; Frank learns that a top officer in his department has a dark past.
After a woman is murdered in her apartment, Danny and Baez turn to her daughter for help, but instead she complicates the investigation; someone from Jamie and Eddie's past launches a smear campaign against them.
Frank's longtime friend Lenny reveals than an upcoming exposé will air some of the NYPD's dirty laundry; Erin must decide how to charge a doctor whose experimental treatments led to the death of his terminally ill daughter.
Frank considers implementing a fitness test after an officer has trouble keeping up with his partner; Danny is hesitant to pursue a cold case after learning who the original detective was; Anthony begs Erin to stall a trial.
After someone breaks into Luis Delgado's home and kills his wife, Luis and Danny team up to take down the vicious murderer who may also be responsible for Linda's death; Frank finally meets Eddie's mother; Jamie and Erin are at odds.
Erin must convince Frank to back a new state police bill of a bargain she made with Gov. Mendez; Danny and Baez pursue the same perp twice after the DA's office is unconvinced by their initial lineup; a cop killer comes up for parole.
DNA evidence in a murder case leads Danny and Baez to identical twins with identical alibis. Also, Frank learns Nicky is interviewing for a job at the Justice Coalition, and Jamie visits Eddie's father, Armin, in prison.
As Jamie and Eddie's wedding day approaches, Erin interviews a witness whose story leads her to doubt Eddie's honesty; Danny and Baez unravel the complicated love life of a young man who was murdered; Frank squabbles with the top brass.