After a young girl goes missing, the family argues whether Danny used questionable methods in order to bring her home safely.

A good Samaritan who takes action against a criminal terrorizing the subway has the Reagans pondering the rights and wrongs of vigilantism.

Erin, Frank and Danny work together within the system to find justice when a rape case's primary suspect is protected by diplomatic immunity.

Frank mobilizes the entire NYPD to find the killer of an off-duty police officer who was murdered during a diamond heist.

With a bomb set to detonate in Manhattan, Frank, Danny and the rest of the NYPD search for its whereabouts.

Danny works to discover the source of a deadly narcotic after three teenagers die from a drug overdose.

Erin's family debates her methods when she uses a law-abiding citizen as bait to take down his gang leader brother.

After witnessing a crime in progress, Jamie's suspect is killed in the pursuit. Danny must solve the case to clear Jamie's name and keep Internal Affairs from a full-blown investigation.

Three released prison inmates place the Reagan family in danger.

While Danny investigates the murder of a popular nightclub's doorman, Frank gets information that his ex-partner is covering up crimes.

A 25-year old cold case of Frank's is brought to the forefront when the missing boy's remains are found. Danny and Jackie look into the death of a high-end escort.

When the son of a Russian gangster is killed at his own engagement party, Danny delves into the world of the Russian mob. Meanwhile, Erin is thrown into a high-profile corruption case.

Because it involves classified information and a sleeper cell, Frank assigns Danny to cover the shooting of an undercover counter-terrorism agent.

A drug addict becomes the prime focus of Danny and Jackie's investigation after his girlfriend is kidnapped and held for ransom. Erin and Charles move past the flirting stage.

Is someone out to assassinate the Commissioner or was the shooting random? Danny takes on the assignment to find out the answer.

Nicky rides along with Danny to a crime scene where a girl at a debutante ball has been murdered and she has a difficult time coping after seeing her first murder victim.

As a former Marine, Danny feels personally responsible for finding the killer of a former U.S. Marine war hero.

Just before Danny is to give witness testimony at a Peruvian drug lord's murder trial, Linda is kidnapped. This drug lord has a history of intimidating witnesses.

Danny and Jackie investigate the cut-throat world of fashion after Linda's runway model niece and a reporter are poisoned at a fashion show.

Frank's frustrations rise when the media sensationalizes the murder of a tourist shot and killed outside a trendy Lower East Side restaurant.

Neighbors of the Reagans are murdered and their son becomes the prime suspect. Jamie is convinced he's being pursued by the Blue Templar when his gun goes missing.

When a drug bust points to dirty cops, Frank decides not to involve Internal Affairs in the hopes of taking down and exposing the Blue Templar.