Danny and Baez grapple with a homicide investigation brought to their attention by Maggie, the medium who previously helped them solve a case; Frank looks for a way to help his ex-partner Lenny Ross when Lenny's daughter gets arrested.

Frank and Erin are at odds when Frank learns the district attorney's office keeps a list of officers they consider unreliable; Danny and Baez recruit a retired mobster to assist in an investigation; a predator poses as a ride-share driver.

Frank's esteem for an old friend and late socialite proves to be a mistake when her son threatens to publicly reveal who she really was. Jamie asks Erin for help apprehending a perp who shot at him after learning she chose not to send him to prison six months ago. Eddie clashes with her new boss. Danny drags Baez into a case involving a suspicious grieving couple.

Frank takes one of Jamie's cases to heart when it involves the suspicious death of his friend's wife. Erin receives an unsolved robbery case that proves to be impossible to crack without help from Anthony.

Frank works to vindicate a detective accused of using excessive force. 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 rookie officer.

Frank is conflicted about how to deal with a former cop's gripe about his pension. Jamie helps a friend deal with illicit pictures of his daughter on the internet. Danny hunts down a killer who shot his online prison pen-pal. Anthony confronts the realization that his foster son might not be suited for police work.

Jamie and Frank oppose each other's viewpoints over the public's treatment of cops after rowdy teens pour water on two rookies. Danny and Baez investigate a man who preys on the elderly. Erin is forced to admit her wrongdoings when Jack brings her an old case and claims a man she put away was falsely convicted.

While Henry works as an investigative consultant for child services, he and Danny butt heads over a case involving a man who is volatile toward his wife. Frank is caught in the middle of an ongoing battle between the NYPD and the FDNY. Erin ponders a life-changing opportunity presented to her by the Mayor. Jamie is suspicious about an investigation targeting Eddie's partner.

Erin disagrees with a psychiatric consultant's diagnosis of a nanny accused of abuse. Eddie confronts her boss. Frank is forced to make staffing changes he is skeptical about. A woman claims she heard someone plotting a murder.

After a woman is found dead at a men's-only club, Danny and Baez investigate if her death was an accident or the result of foul play. Frank hears about an alleged affair between the chief of Internal Affairs and the spouse of another member of law enforcement. Jamie and Eddie argue about gender politics in the Reagan family.

After an EMT is shot and killed, Danny and Baez work to determine who is behind a chain of ambulance robberies. Also, Frank defends New York's homeless community after the mayor puts a new law in place; Erin tries to put away a violent perp after a judge rules he's not guilty, and Eddie offers to help Jamie pay off his student loans.

Frank takes heat when a widow blames him for her husband's recent suicide while on the job. When Eddie has a gut feeling about a murder, she and Erin band together to solve the case. A desperate Luis Delgado tells Danny and Baez that the only way he'll testify against his former cartel is if they protect his sons.

Frank must uncover the truth when an undercover officer accuses a fellow cop of police brutality. Danny and Baez investigate the murder of a famous photographer recently accused of assault by his former models. Erin struggles to protect a witness.

Danny and Baez work with Texas Ranger Waylon Gates when they are put on a case to find the Lone Star Killer. After Eddie's partner mistakenly shoots an undercover cop, Internal Affairs accuses Jamie of not supervising properly.

Jamie is under investigation after his police vest is found on a perp. Frank debates whether to aid and protect an old friend whose home was invaded. Danny and Baez investigate the suspicious circumstances surrounding the death of a hotel employee believed to be a suicide. Erin asks Anthony to make a deal with a man who knows secrets about the current D.A.

Frank and Garrett try to convince Mayor Chase to work better with others to properly run the city. Danny and Baez try to track down the person who vandalized several NYPD vehicles with anti-cop graffiti. Erin is shaken after a car accident.

Erin and Anthony must trust a sociopath who claims he has evidence to convict a double-murderer. Frank faces backlash from his department when he suspends an officer for violent behavior. Danny and Baez try to arrest a notorious gangster who appears to have people covering for him inside the department.

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

After getting a match from an unknown relative from a DNA network, Sean Reagan does some detective work to figure out who this mystery person might be. Frank gets a personal request from a woman to transfer her son to a safer assignment. Also, Danny seeks to uncover the truth behind the murder of a key witness in one of Erin's cases, and Eddie begins to think about having a child after she and Jamie discover a newborn left outside their precinct.