The gritty details of life as a member of a New York City police unit.
Kelly risks the consequences when he testifies on Licalsi's behalf and IAB begins to investigate him. Sipowicz works with an abused woman who's reluctant to testify against her husband. The detectives investigate robberies of drug dealers in their apartments. John tells Robin about the feelings he still carries for Janice. Sipowicz's AA sponsor wants him to agree to abide by a contract before he lets him try to restart his relationship with Sylvia. Donna tries to give Greg advice about dealing with his divorce.
IAB begins to investigate Kelly and Sipowicz's busting of the officers they caught robbing drug dealer's apartments, then they begin looking into Kelly's handling of the notebook, that was part of Medavoy's case. Roberts drops by the station with a gift for Kelly. Sipowicz & Kelly investigate a double murder. Licalsi takes the stand in her trial and the verdict comes back. Andy tries to have dinner with Sylvia, but things keep coming up; eventually they get together.
Fancy catches Donna & Greg in an embrace. The abused woman Andy helped a couple of weeks ago, turns into a homicide. A new female detective, Lesniak, transfers into the squad, because of a relationship at her former precinct, and begins to work with Andy on a case. Kelly works with a Chinese detective in the investigation of the murder of an off-duty cop in Chinatown. Lesniak's ex-lover drops by and causes trouble for her. Fancy gives Greg a friendly warning about relationships in the workplace.
A baby in a car is the innocent victim of an apparent drive-by shooting. Lois contacts Andy because a cop she was entertaining died in a compromising position. Andy moves the body to a less conspicuous location. Lesniak's ex-lover keeps harassing her. Kelly's future with the police department is decided as IAB comes to the precinct to reinvestigate some of his old cases. Haverill has Kelly transferred to borough dispatch duty. Kelly's reaction is to quit.
An over-the-edge Abruzzo threatens Lesniak in the squad room. Bobby Simone, a widower & racing homing pigeon breeder, joins the precinct. His first assignment is to help Sipowicz in the investigation of the hit on a mobster's son, where a stray bullet also strikes an elderly woman in her apartment. Lesniak tries to help a woman who's worried that her husband is molesting their daughter.
After looking into it, Simone and Sipowicz suspect a chiropractor of murdering his wife. A woman, whom Bobby knows, finds her 11-year-old son in possession of a gun. Medavoy changes to a high-fiber diet. While moonlighting as a security guard for Roberts, Martinez becomes attracted to the college student he's been assigned to protect and she's worried about her father. Next week, Andy and Sylvia will move in together, but first they take a shower.
Donna's sister Dana moves in with her and Greg; later she tries to move in on Greg. Shots are fired at the school across the street, but Bobby doubts the confession of his friend's son, the 11-year-old murder suspect in a gang related shooting. A lothario appears to be targeted by a woman he's infected with HIV, Lesniak and Martinez try to bring him down for reckless endangerment.
Andy's AA sponsor is beaten up by his estranged son. Simone and Sipowicz investigate the murder of a pregnant woman whose charred body leaves few clues. Martinez and Medavoy check out the story of a man who might have information about a pawn shop robbery.
The detectives investigate the murder of a gay bar owner. Fancy's wife is ready to have the baby. Medavoy's neighbor is the victim of a fortuneteller's scam, the resulting curse gives him a rash. Breen breaks his promise to Andy by checking up on his son, he decides to go back to him, a mistake that proves to be fatal.
Lesniak is flashed, brings the perpetrator in and deals with his "high priced lawyer and shrink," especially when he repeats the offense. Another detective uses his pull to take a possible serial killer case away from Bobby after he brings in a possible suspect. One of Fancy's old contacts, Vinnie Greco, brings in a tip about a couple of guys looking for some heavy hardware to do an armored car job; Sipowicz works with him but the guy is really working for someone else against Fancy. Fancy discovers this and has Vinnie wear a wire for him. Andy invites his son over for dinner and finds out Andy Jr. is joining the Air Force; later, Andy proposes to Sylvia; this time she accepts.
After discovering a key piece of evidence, Simone gets his chance to question the serial killer suspect. The detectives work on stopping the armored car robbery and then Fancy plays the incriminating tape that he had Vinnie record for him. Haverill is given the choice of retiring or a trial and he elects retirement. Martinez and Lesniak arrest an odd extortionist. James tells Adrianne that he enjoys working with her.
Simone & Sipowicz investigate the brutal murder of the daughter of woman whose ex-husband has made threats against her. Lesniak and Martinez's case involves a con artist who sells a black box to homely women, promising them beautiful skin. The new Borough Commander checks in and lets Fancy know his overtime policy; that doesn't sit well with Sipowicz when it compounds their investigation. Bobby's childhood friend is involved with a nightclub that is frequented by wiseguys.
Andy disagrees with Sylvia over the wedding arrangements, he wants a quick trip to Maryland and she wants a traditional Greek Orthodox service. An execution-style murder of three people at a fast food restaurant is investigated by Simone & Sipowicz. Lesniak meets an old high school friend, who's now a doctor, while investigating a rape case with Martinez, who develops a case of jealousy. Andy and Bobby travel upstate when a potential suspect is caught there, Bobby uses the trip as a chance to let his pigeons get a workout.
Evidence in the death of a pimp points to a cop that once helped Andy out with a problem. Bobby mentions the case to his girlfriend, the reporter, and later regrets it when the story hits the papers. Donna's former lover, Harold, the ex-New York Ranger, returns to the city and meets with Donna and Greg overreacts. James tells Greg about his interest in Adrianne.
Bobby and Andy collide with a Rumanian immigrant who has a woman locked in the trunk of his car, later investigation shows him to be a terrorist. While transporting the serial killer out of the station house, the Webster serial killer is shot and his last victim's father is on the premises. Bobby begins to investigate the father and another member of a victim's support group. Greg tries to talk with Dana about his relationship with Donna, but she takes advantage of the situation. James asks Adrianne out for dinner; however, she rejects him because she does not want to be involved in relationship with someone she works with, given her previous history.
Simone and Sipowicz investigate the murder of a Puerto Rican teen because he used to make some paintings in Little Italy. Greg meets Donna's former lover and she makes a decision about her relationship with him. Sylvia is mugged and later tells Andy a secret from her past.
Bobby's emotionally fragile witness for a double-murder keeps changing her story, she is really only interested in him. A family run business, that Andy used to work in, is held up and the owner's wife is killed, he participates in the investigation that involves some of his old friends. Donna's temporary replacement is gay. James enters in a department boxing tournament.
The detective's search for a killer following a shooting spree, where a rookie cop's missed shot also kills a bystander. Fancy's brother, a cop in the 8th precinct has racial troubles with his commanding officer and Arthur intercedes on his behalf and his own boss covers for him during their crisis. Andy goes to the doctor and finds out that he has an enlarged prostate, Sylvia thought their lack of sexual activity was because of the incident from her past that she had told Andy about. When Andy and Bobby go back to the apartment where the shooter lived, they discover he has returned, resulting in Bobby saving Andy's life.
Fancy works with James to help him get ready for the boxing tournament. Simone is attracted to an undercover cop that works with him on an arson sting. A woman that Sipowicz gets to testify in a case is murdered by the men she was going to testify against.
The detectives search for the killer of a bookie. Donna returns ready to resume her position. Bobby's head case witness tries to end his career, when he won't give her what she wants. John gives all of the detectives farewell greeting cards; later, Fancy proposes that he move upstairs to anti-crime where there is an opportunity. Andy and Sylvia meet with the priest and later Sylvia hears a story about what has contributed to Andy's loss of faith. Andy smells something familiar on Russell.
A witness smells alcohol on Russell's breath. Officers in another precinct bash John and his lover, so he asks Bobby for some help. A terminally ill infant helps the detectives locate a serial rapist. Bobby confronts Russell about her drinking. Greg meets with his wife who would like them to get back together for the kids and Donna tells him where their relationship stands. When Kelly can't get back for it, Andy asks Bobby to be his best man.
Two years ago he called her a "pissy little bitch," tomorrow he will call her "Mrs. Sipowicz," pre-wedding jitters put Andy in rare form. Russell's problem makes her miss getting a gun off a suspect and Bobby isn't happy about it; later she admits to having a problem. Fancy's brother, still having trouble with his sergeant and he is being investigated by the IAB, Bobby and the squad work to help clear his name. James goes out with Adrianne. Greg brings his wife to the wedding. Andy Jr. makes it to the ceremony.