A dangerous criminal from Danny's past comes back to seek revenge and kidnaps Jackie. Meanwhile, Jamie meets his new partner. Michael Madsen and Corbin Bleu guest star.

When an injured woman recants her claim of domestic violence, Danny and Jackie look into it further only to find that the woman is involved in a secret relationship with a high powered councilman who also happens to be a friend of Frank.

Erin's ex-husband returns to town and opposes her in court. Frank spends the day with a young man who won a contest and he tells Frank that he doesn't think that the police give equal priority. He talks about how his mother was killed and how it's still unsolved. Danny is investigating the murder of two men who along with two others were charged with raping a girl, but because of a technicality they got off. Danny wonders if he should really give it his all.

Danny and Jackie set out to investigate the murder of a bride on her wedding day in a drive-by gang shooting. However, they are pulled off the case and assigned to the protection detail of a Central American president who they believe is a target for assassination.

A detective who was instrumental in the arrest of a Malaysian drug dealer is kidnapped by the drug dealer's brother who threatens to kill the detective if his brother is not released. Frank's stance is not to negotiate with terrorists so he has Danny and the detective's partner try to find him. Henry joins Jamie on a ride-along and, when he sees how Jamie works, Jamie can't help but worry that Henry doesn't approve of his methods.

When Erin's key witness, an infamous photographer, is nearly killed in a hit and run, she arranges for Danny to work protection detail to safeguard him.

Danny is called to the scene on Halloween night, when a man in a priest costume is attacked by a figure dressed as a skeleton. Detective Kate Lansing is assigned to help on the case and she recognizes the skeleton costume as the garb of Baron Samedi, a Haitian spirit of death.

Danny arrives at a college campus to find a murdered student, who was thought to be dealing drugs.

Danny is investigating the shooting of a man who's an ex-con, and there's a lot of people who wants to see him dead. The man dies in the hospital and he asks for a priest to give him the last rites. Danny learns of this and asks the priest to tell him what the man said but the priest refuses to say anything. A known criminal lawyer Frank knows gives him some information but Frank is not sure if he should believe the lawyer. And Henry is mugged and Jamie is determined to find the one who mugged him.

When two motorists driving gas-guzzling cars die at the hands of a sniper, Danny and Kate are put on the case of what the city believes is the work of a radical environmental serial killer.

Jamie must deal with the emotional consequences of his actions on the job. Susie Essman and Annabella Sciorra guest star.

Danny is pulled over by a cop who asks if he can look what he has in the back of his vehicle. Danny asks him what's going on, he says he got a tip that a vehicle like the one Danny is using, was at a drug buy. Danny thinking it's outrageous and lets him look but the cop finds some drugs and arrests Danny. When the family learns of this, Linda wants Frank to intervene and he doesn't think he should and he says that's for everyone. Henry asks Erin's ex to defend Danny and he does by making him question his trust of his partner. And when he sees her with the IAB Captain investigating him, he wonders if he can trust her.

When a man with multiple rat bites is thrown from a moving car, Danny works the case to find out why and who was trying to send a message. Mary Elizabeth Mastrantonio and Mark Moses guest star.

The former mayor gingerly approaches Frank after Jamie arrested his spoiled-rotten brat daughter, by the book, for drug possession and gross disrespect, which continues even in court. While Henry attends the funeral of his Hassidic friend, the New York grand rabbi, his junior son and designated successor is fatally stabbed just outdoors. Thus the firstborn, traditional successor becomes grand rabbi and prime suspect, or his bodyguard. Investigating, Danny and ex-Hassidic fellow detective Wolf Landsman find further possible motives in the rabbinical family's secret love life and consider further strong-armed acolytes opportunities.

When a 10-year-old boy is the victim of an incident in the projects, Danny's heated approach to the case lands him in anger management class.

Danny and Jamie are playing basketball with some other guys. A guy Danny knows gets into it with a guy Jamie knows; the guy Danhy knows smacks the guy Jamie knows. The one who was smacked has to be hospitalized and he demands that the one who smacked him be arrested and Danny reluctantly does it. He tells the guy he knows that his sister is the D.A. and maybe he can talk to her. Erin is approached by a man who asks her to re investigate his daughter's unsolved murder which is 15 years old. Erin goes to Danny and asks him to look into the man's daughter's murder. It seems the man thinks that his daughter's boyfriend who's the son of a wealthy man should be considered. Danny agrees, if she helps his friend. Danny goes to see the detective who investigated the murder and he tells Danny that he had an alibi and took a polygraph and passed. Erin informs Danny that his friend has a previous record which means he has to be indicted. Jamie offers to talk to the guy he knows. Erin and Danny see the man and tell them what they learned. He tells them that the guy's father's company has polygraph which he could have learned how to beat it. And he also tells them that his alibi witness was a friend. So Danny decides to look deeper. Frank and Garrett have a disagreement when Frank is interviewed and a very touchy question is asked.

Amid protests over the NYPD's new "stop, question and search" policy, Erin and the entire Reagan family are targeted by a protest group's photographer, who is publishing the photos to a website. When a rape victim that Erin is preparing for trial appears in some of the photos, Erin confronts the photographer. Danny and Detective Maria Baez investigate a young "Bonnie and Clyde" type couple who rob a bank and steal an off-duty police officer's gun in the process, but the intrusion of the FBI threatens their progress. Elsewhere, Frank considers getting romantically involved with an ACLU representative named Whitney, who is an acquaintance of Erin's and close to Erin's age.

When a man is shot in Times Square, Danny investigates and learns the man had no enemies or reason for someone to kill him. Another person is killed and there appears to be no connection between the two victims. He later learns that the second victim got away with murder so he thinks someone is trying to get payback. Erin takes him to the D.A. who prosecuted the second victim. The man's irate about the victim because he feels she should have been convicted. When a third person is killed, Erin figures out what the link is. Jamie finds a boy wandering the streets with blood on his clothes. He takes him back to his parents and can't help but wonder if there's anything wrong at their home. An astronaut who just retired, who's also a friend of Frank, comes to the New York. They meet and the man drinks very heavily and talks about his family, but Frank learns the things he said about his family are not true and tries to help him.

The body of a girl is found in the cemetery laid out as if she was being prepared for burial with a cross in her hands. Danny investigates and talks to her father, who says she's a very devout Catholic girl. But when they talk to her friends they discover that she's keeping secrets from her father. Frank learns that a former NYPD cop shot two cops in Miami, killing one of them after being rejected. It seems like the cop was fired from the NYPD. And Frank fears that he might be coming to New York to go after the ones who go him booted from the Force.

Danny was about to apprehend a known drug dealer but a man who accompanied him starts shooting and even the dealer is hit. Danny goes to the hospital to talk to him but Linda won't let him. Later the shooter kills someone else. And when the dealer dies, Danny is upset with Linda. Danny asks Jamie to help his son with a soap box derby that the family has won since Frank joined. And a rival family tells them, they're going to get them. And Henry reveals to Frank why they've been winning. And Erin is promoted. On her first day, one of the prosecutors, tells her she prosecuting a case and the defendant is facing his third strike. So she looked at his previous convictions and learns that one of them might be questionable and Erin looks into it and the one who prosecuted it was the person who promoted her.

When a man is found wandering the street with blood all over his clothes, Danny and Baez try to find out what happened but the man says he doesn't remember. He says he's from out of town and he's with his girlfriend and that he's planning to propose to her. They go back to his hotel room and find his girlfriend dead and blood all over the room. While the guy still maintains not to know anything, Danny has no choice but to take him in. Danny's not sure what to believe. An off duty cop who was drinking comes across a robbery and stops it. Later, Jamie shows up and smells that he's been drinking and tries to help him but the Captain sees what he's doing and orders that the cop be tested. When he comes out positive, he has to face a hearing. Frank, who admires what he did, but believes in following the rules. And Erin gets a call from her daughter's school who informs her that her daughter is planning some kind of protest and if she goes through with it, she'll face suspension.

Danny gets a call to go to a project where a gang rules with fear and intimidation. Jamie finds a girl standing on the roof holding her baby, saying she can't stand their lives being controlled by street gang Los Lordes so she jumps to death with her baby. Danny later learns that the girl was someone he met when she was younger when her parents died and he said he would help her and her sister. Danny goes to her sister who is bitter that Danny forgot about them. He learns that she is now with the leader of the gang. While Jamie and his partner are walking through the project there's some shooting and Jamie's partner is hit. Frank later learns that the D.A. is not pressing to prosecute the gang so Frank goes to the mayor for help.

As the Reagans rally together to take down the leader of the gang responsible for the murder of someone close to them, Danny looks to the gang leader's girlfriend to lead them to him.