Episode 1 : Mercy
When a supporter for the mayor elect is found dead, Frank is put on the spot when the mayor wants him to position it to the public as a random act of violence. Meanwhile, Jamie goes undercover at a bar and meets a suspicious patron.
Episode 2 : Friendly Fire
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.
Episode 3 : Critical Condition
When three men attempt to rob a bank, Danny discovers that one of the perps happens to be a former cop. Meanwhile, Jamie works with a new partner, Luisa Sosa (guest star Monica Raymund).
Episode 4 : Innocence
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.
Episode 5 : A Night on the Town
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.
Episode 6 : Black and Blue
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.
Episode 8 : Thanksgiving
When a young woman commits suicide, Danny and Jackie suspect it was forced. Meanwhile, Frank and Mayor Poole butt heads over a threat to the city, and when Henry suffers a heart attack, the Reagans must face the possibility of losing their patriarch.
Episode 9 : Moonlighting
Danny accompanies a dangerous ex-mobster who is helping him find bodies on cold cases in exchange for leniency for his son on grand theft auto. Meanwhile, Jamie works undercover in a boiler room operation, looking for a secret about the Sanfino family.
Episode 10 : Whistle Blower
When Erin's informant is murdered, she blames herself and works to help Danny discover who killed him.
Episode 11 : The Uniform
Danny and Jackie investigate a murder scene at a diner, where a witness claims a uniformed officer fled the scene after shots were fired.
Episode 12 : The Job
On the way home with his family, Danny hits a man with his car who is fleeing from a gunman, and his family gets caught in the crossfire when Danny fires his weapon at the gunman. Frank deals with 9/11 guilt from impending loss of a friend whom he worked alongside at Ground Zero.
Episode 15 : The Life We Chose
When a Reagan family friend, an undercover detective, is killed, Linda and the boys worry about Danny, as his relentless search for the killer takes a toll on his emotional state.
Episode 17 : Reagan V. Reagan
As Erin prosecutes a woman accused of killing her husband, the defendant's attorney is murdered and Danny is assigned to the investigation. When Danny is out on the stand to be questioned, things get heated between the brother and sister.