The family argues over Danny's questionable tactics as he searches for a missing girl; Jamie starts his new life as a cop.
A good Samaritan with a police record takes action against a terrorizing subway criminal, forcing the Reagans to weigh the rights and wrongs of vigilantism.
Danny, Erin and Frank work together to seek justice when the main suspect in a rape case is protected by diplomatic immunity.
When an off-duty police officer is killed during a diamond heist, the entire NYPD searches for the person responsible.
The Reagans argue the advantages and disadvantages of profiling; Danny, Frank and the rest of the NYPD search for a homemade bomb about to detonate.
Three teenagers die from drug overdose, and Danny sets out to find their narcotic source and bring the responsible to justice.
The family questions Erin's tactics when she tries to take down a gang leader by using his law-abiding brother as bait.
After witnessing a crime in progress, Jamie pursues a suspect; Danny has to help Jamie avoid an internal affairs investigation.
Erin becomes the subject of a personal and deadly vendetta when a reviled rapist and murderer she put away is released from jail.
Danny investigates when a doorman at a nightclub is murdered; Frank makes a decision about a former partner's future.
Danny and Jackie investigate the murder of a high-end escort after her body is found floating in the East River.
Danny must delve into the family politics of the Russian mob while investigating the death of a gangster's son; Erin becomes involved in a high-profile corruption case.
Danny investigates the shooting of an undercover counterterrorism agent who was involved with infiltrating a sleeper cell.
When a girl is kidnapped, Jackie and Danny suspect her drug-addicted boyfriend is responsible; Erin's relationship with her boss takes a step forward.
Frank is lucky to survive a stranger's assassination attempt, an act that prompts a citywide manhunt.
A young girl is murdered at a debutante ball; Danny gets into an fight with his sister for bringing Nikki to a crime scene.
Danny vows to find the killer of a war hero who was homeless; false information about Frank leaks to the press.
After Danny witnesses a murder, a member of his family is put in jeopardy in an attempt to stop him from testifying.
Jackie and Danny investigate when a reporter and Linda's niece, a runway model, both collapse at a fashion show.
Frank's distress rises after the press makes a big fuzz out of the killing of a tourist right in front of a trendy Lower East Side restaurant.
An alcohol and drug addict comes under suspicion when his family is murdered; when Jamie's gun disappears, he believes that he is being set up.