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. Danny seeks to uncover the truth behind the murder of a key witness in one of Erin's cases. Eddie begins to think about having a child after she and Jamie discover a newborn left outside their precinct.

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.

A widow blames Frank for her husband's recent suicide. Eddie has a gut feeling about a murder. A desperate Luis Delgado wants protection for his sons.

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 DA’s office keeps a list of “unreliable” cops. Danny and Baez recruit retired mobster Vincent Rella to assist in an investigation. Jamie participates in a decoy operation to take down a predator posing as a ride-share driver.

Frank's esteem for an old friend proves to be a mistake. 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.

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.

Frank and Garrett devise a plan to convince Mayor Chase to work better with others in order to properly run the city. Danny and Baez try to track down a perp who vandalized several NYPD vehicles with anti-police graffiti and made threats against officers. Erin is shaken after a car accident. Eddie and Jamie argue about whether they should keep a stray dog who leads them to a crime scene.

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.

Frank takes one of Jamie’s cases to heart when it involves the suspicious death of his friend’s terminally ill wife. After demanding more meaningful cases, Erin receives an unsolved robbery case that proves to be impossible to crack without help from Anthony. Danny and Baez uncover the shocking truth behind a puzzling assault claim.

Frank is conflicted about how to deal with former cop Rick Austin’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 realizes that his foster son might not be suited for police work.

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 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 after the mayor puts a new law in place. Eddie offers to help Jamie pay off his student loans.

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 DA.

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

Frank works to vindicate Detective McKenzie, who is 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 the relationship between Espinoza and a new rookie officer. Eddie goes undercover to help Erin investigate a mysterious cult.

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 Mayor Peter Chase. Jamie is suspicious about an investigation targeting Eddie's partner.

Frank must uncover the truth when an undercover officer accuses a fellow cop of 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 as new justice reform laws go into effect.

After a woman is found dead at a men's-only club, Danny and Baez investigate if her death was an accident. Frank hears about an alleged affair between the chief of Internal Affairs and the spouse of another member of law enforcement.