A married, family man and supporter of the new Mayor, involved with a Croatian girl, is shot dead. The Mayor is averse to bad press. Frank stays on as Commissioner. Plain-clothed Jamie unknowingly helps a mob member who had over-dosed.
When Danny shoots a cop who failed to identify himself, he is put on modified assignment and must face an Internal Affairs investigation, which delves into his personal state of mind that day.
When a bank robbery turns into a hostage situation, Frank realizes that the perp is a former cop and old friend who has resorted to crime because of his daughter's desperate illness.
Erin reopens an 18-year-old rape case in which Frank was the arresting officer. Meanwhile, Danny and Jackie investigate the murder of three teenagers in a park who seemed to have been killed for no reason.
Danny tries to juggle investigating a case with trying to have a romantic weekend with Linda. Meanwhile, Jamie goes deep undercover into a crime family.
Frank deals with a political crisis after Jamie and Renzulli enter a religious center in response to a 911 call and are injured by the church's security team who prohibits them from entering.
An escort is murdered in a hotel room. Sensing a pattern, Jackie poses as a decoy escort. Frank has budget constraints but resisting unions. Henry declines a consultant's role in a private agency looking to profit from outsourcing in NYPD.
A girl falls from her apartment window and dies. Danny investigates. Henry has a heart attack and spends Thanksgiving in the hospital. Tony gets cash to square off his gambling debt, with a warning from the Commissioner.
Jamie goes undercover in a boiler room operation, selling stocks on cold calls, to get their client list with criminal links. Danny drives around a convicted mobster who reveals murdered bodies, in a deal to help his carjacking son.
A whistle blower and Erin's confidential informant is killed. Danny investigates and a personal angle to his killing is unearthed. Frank exposes an edited video which was disparaging towards the police force.
Danny, returning with his family in their car, bumps into a man. Shots are fired, and they miss hurting his family. Frank speaks at his partner's wake, who went on disability after rescuing more than 100 from the North Tower on 9-11.
A woman is found dead. The daughter reports a murder while her step father reports a death. Danny investigates. Frank's support is sought for the canonization of a priest of his parish. Unsure, he probes and gives meaningful feedback.
Nicky gets a reality check when her absent father shrugs her off. An illegal immigrant is robbed of his cash. His son accidentally kills the robber. Danny coaches the son in making a statement which would get him a lower sentence.
An undercover operation is underway to trace a drug pipeline. Two detectives get shot, killing one. Danny investigates along with the entire police force, out to avenge the killing. Nicky and Henry dance and sing in a show.
Un reporter famoso, grande amico di Frank, viene aggredito mentre si trova in città. Nel frattempo, il caso per cui Jamie sta lavorando sotto copertura arriva a un punto critico.
In the course of a murder case trial, another murder takes place and Danny, the detective, finds himself pitted against Erin, his prosecutor-sister, in the courtroom. Frank's onyx credit card is misused after fraudulent duplication.
A reverend, the mayor and the police organize a gun buyback plan, with no questions asked. There, a gun used in a shooting at a chemist's is traded in. Danny investigates without being able to use the evidence from the buyback program.
Jamie saves a baby from an apartment fire but Renzulli gets the credit so that his cover remains intact. A fireman's 11-year-old son, a school friend of Danny's son, feels that his father did not commit suicide. Danny investigates.
Erin's witness in the murder trial of a violent mobster is killed before giving testimony. Due to a leak, the next witness is threatened, but protected by Danny and Jack. Erin is offered the Deputy Mayor's position, but she declines.
A man dies in the reception area of a hospital. The investigation leads to an illegal fight club with heavy betting. The fight was doctored by cementing the gloves of one fighter. Jamie's cover is blown, and he saves Noble from a mob hit.
The police come to know of a citywide biological threat and Frank deals with it. Danny, hunting for a petty thief, gets a tip which helps resolve one of his unsolved cases. Jamie and Danny argue about booking rights for this petty thief.
