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.

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.

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

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.