A suitcase containing eighty pounds of cocaine is stolen by a small-time dealer (Jack Kehler) after a light aircraft crash. Sid the Snitch and Buntz get involved as potential buyers, but a more-established dealer kills the small-time dealer and kidnaps Buntz at gunpoint; Buntz eventually kills him. (This plot line initially appears to be self-contained, but returns in the final two episodes of the series, setting up a spinoff series.) Belker is undercover among homeless people looking into a hotel-voucher scam. Goldblume investigates a case of poison substituted for aspirin tablets at a drug store. Jablonski's angina is worsening, and Furillo threatens to involuntarily retire him if he doesn't seek medical care.

After Hunter shoots a boy caught robbing a convenience store, Internal Affairs finds that neither his firearm nor the bullets used were department-issue, leaving Hunter subject to dismissal from the force; Belker struggles to protect senior citizens from a violent mugger; the public defenders are engaging in a work slow-down to protest recent cuts in their workforce, eventually electing to strike.; Judge Wachtel insults Davenport repeatedly from the bench, leading Davenport to slap him across the face and Wachtel to have her arrested for battery; Jablonski takes voluntary retirement in the face of upcoming coronary artery bypass surgery.

Hunter is demoted to Sergeant as a result of the Internal Affairs investigation, and Furillo convinces him to take over the Desk Sergeant position; with the public defenders on strike, the officers must use discretion in making borderline arrests as the station overflows with suspects; Belker finds the storeowner cashing the checks of the mugged senior citizens; while Belker tries to get the name of the criminal from the shopowner, LaRue reopens the store - acting as the storeowner - and catches the criminal when he comes in to cash another stolen check; the public defenders return to work after the cuts are rescinded; Jablonski undergoes successful bypass surgery. Robert Clohessy (Officer Patrick Flaherty) joins the opening credits.

Chief Daniels asks Furillo to intervene at the Polk Avenue Precinct, where racial tensions are simmering and Captain Calletano - derisively nicknamed "Captain Taco" by his officers (a nickname that first cropped up in episode 6.7) - has been unable to control the tensions, but Calletano denies there is a problem and vehemently resists help; Furillo looks on sadly as a brawl between white and black Polk Avenue officers erupts after a black officer is shot, and Calletano is unable to stop it; Internal Affairs is investigating Buntz after several people he has arrested have been burglarized while in custody; Buntz traces the burglaries to the man feeding names to Sid the Snitch, who has been forwarding those names to Buntz for arrest; Hill becomes a minor celebrity after catching a baby thrown from a fourth-story window. Rene Enriquez (Captain Ray Calletano) returns to the opening credits; James B. Sikking (Sgt. Howard Hunter) now appears in the credits wearing his Desk Sergeant's blues instead of his EAT khakis. Added to the guest star credits (after the opening credits) is "Also Starring Jon Cypher as Chief Daniels". Chazz Palminteri appears as Sonny Cappelito.

After Captain Calletano loses command of Polk Avenue and is reassigned to Division, he threatens to go to the press; several Polk Avenue officers are fired outright or reassigned; Officer James Sanders is transferred to Hill Street and is treated as a pariah; a college friend of Goldblume turns vigilante, with fatal consequences for criminals, police, and ultimately himself; Renko's damaged car is stolen by a hood who offers to get him full replacement cost from his insurance; Renko backs out, and the hood returns his car; Buntz explains his hostility for Flaherty - Flaherty turned in his partner, an old friend of Buntz's; a hit man attempts to kill Sid, but Buntz kills the hit man instead; Jablonski asks to return to the police force. Megan Gallagher (Officer Tina Russo) is added to the opening credits; Betty Thomas (Sgt. Bates) takes over Robert Prosky's (Retired Sgt. Stan Jablonski) spot, while Prosky now appears not wearing a police uniform.

Renowned mobster "Uncle John" Petruzzi is expected to be assassinated prior to going to jail; Russo is beaten and raped by her mobster "boyfriend" while trying to discover the location and time of the hit; Belker counsels Russo on how to be an undercover cop; LaRue and Washington arrest a purse snatcher who then confesses to several high-profile murders, but further research reveals that he has not committed the crimes; Furillo has to intervene to help Ray Calletano, who is testing Chief Daniels' patience to the limit, and Calletano decides to resign; Jablonski assists Belker on an arrest. Taurean Blacque's credit is re-shot to reflect his shaving off his beard.

Grace Gardner, a character from the early seasons who dated Sergeant Esterhaus, returns as a nun planning outreach work on the Hill and Flaherty is assigned as liaison; Councilman Wade, out for personal glory, repeatedly jeopardizes the precinct's battle against drugs, shoots an unarmed juvenile dealer, claiming self-defense, and is arrested by Washington; Belker and Buntz (separately) are working on drug busts; Buntz is forced to delay his bust due to a lack of supporting officers and has his finger cut off in retaliation by the loan shark who bankrolled his buy; Jablonski is hoping to return to police work, but experiences a flare of his chest pain and is not cleared by the police surgeon; Goldblume has a new lady in his life: the producer of a TV talk show. Rene Enriquez is removed from the opening credits because of his AIDS.

Councilman Wade attempts to derail Furillo's investigation of his shooting by revealing details from Washington's personnel file to the press to discredit the detective; Furillo and Washington discover the conspiracy that allowed Wade access to Washington's file, and Wade is arrested for the conspiracy; Grace Gardner's vocation is challenged by her attraction to Flaherty; Buntz chooses to be the one who arrests the loan shark who clipped his finger, but though he tries for a clean bust, the loan shark pulls a gun and Buntz is forced to shoot him; a literary agent, unimpressed by the manuscript of Goldblume's deceased friend, offers Goldblume the chance to write his memoirs. Robert Prosky is removed from the opening credits; Frances Conroy plays a customer of the car park Belker is undercover at, and Brian George plays a real estate agent.

Captain Furillo is advised that his father was shot and killed during a robbery; when he investigates and discovers that his father had a brain tumor and killed himself due to the pain, for his mother's sake Furillo disposes of the suicide weapon and uses his pull with the police to avoid having the case classified as a suicide; Belker - who has been suffering from nightmares regarding nuclear war - takes charge of an abandoned baby and then gets involved with the father's plight; a Korean restaurateur tows LaRue's car from his parking lot and LaRue retaliates by releasing rats in his restaurant and notifying the Board of Health. Unusually, this episode includes several dream sequences and a flashback.

Racial tensions escalate when a white undercover officer (Sam McMurray) shoots his black partner; Buntz has temporarily lost his sight and goes undercover with Belker, posing as a beggar; a store-owner causes disturbance by displaying Nazi artefacts in his store; enraged because he was made to look like a liar in front of his black officers, Furillo strong-arms Chief Daniels into an apology to them over the shooting incident--and gets unexpected help when detective Patricia Mayo storms into Daniels' office during their meeting and resigns from the force over Daniels' unethical police pressures to renew their personal relationship. James McDaniel plays Mason, one of the black officers.

LaRue thinks he has a chance with a new public defender, Sharon Fein, until she asks Washington for a date; later that day, Fein allows a criminal in the interrogation room to snatch a gun from her; he kidnaps Davenport at gunpoint and decamps from the station, eventually becoming holed up at a convenience store after shooting the owner; Davenport manages to broker an amnesty; Belker wrecks a car belonging to LaRue's brother-in-law while chasing a robber, and the car is later discovered to contain stolen parts; Sharon and Washington's date involves dinner with her parents, whose behavior sours Washington on becoming involved with her.

Jablonski, Renko and Hill go on a deer-hunting weekend; after being accosted by state troopers, breaking into the wrong cabin, and recalling war-time experiences, the weekend is cut short when Hill steps on a spike during the hunt; Henry Goldblume, who had planned to join them, is sidetracked by a speech to the Boy Scouts, an unstable woman who accuses him of raping her in the Captain's office, and a lack of money; he is then kidnapped by a serial robber who, upon learning that Goldblume is a police officer, forces him to dig his own grave before leaving in Goldblume's car; Officer McBride voices uncertainty and regret after shooting an armed robber, until Buntz mentors her. Unusually, this episode starts with the opening credits - no Roll Call or other pre-credits footage. The episode was playwright David Mamet's first script ever accepted for television, which included the recurring character played by his wife, Lindsay Crouse.[8] Robert Prosky returns to the opening credits---shown in a T-shirt instead of his former police uniform. Also, in the first act after the intro, Jablonski's alarm clock suggests the time of day to be just after 5:30 A.M.

During a strike by refuse collectors, the police take over collections, with dramatic consequences when a gangland funeral interferes with a refuse collection route; Hunter is asked to take command of an EAT unit at a siege after their lieutenant is injured by the gunman, who turns out to be none other than Jack Ballantine, Hunter's former EAT second-in-command; Russo and Flaherty try to deal with an angry old deaf man who has been in a fight with crack addicts and who ends up shot by police after he doesn't hear their command to drop his shotgun; Russo and Flaherty sleep together.

LaRue becomes obsessed with a radio contest to find the largest live cockroach; he loses the contest, but busts a wanted felon when he shows up to enter the contest; Buntz is worried about the state of Furillo's marriage, based on a (erroneous) tip; a drug user, released on bail after Goldblume changes his charge from a felony to a misdemeanor, kills a grandmother while intoxicated; Goldblume is suspended, but takes his complaints regarding understaffing to Chief Daniels and TV, with his actions resulting in not only a reversal of his suspension but also an authorization for 3 new judges, 40 new police cadets, and a study for building a new prison; Belker adopts a dog whose previous owner had trained him to snatch purses.

Due to a clerical change, the Hill Street Precinct is $130,000 short of their quota for seized narcotics, and is at risk of losing funding for overtime, and Buntz, in command for the day, mounts a campaign to meet the quota; Belker busts a tough kid named "Fetch" who bites and runs drugs; Russo and Flaherty bust a disowned snitch who tips them to a mobile drug lab, but the bust literally goes up in flames; Inspector Scapizzi sends his new girlfriend to the Hill to redecorate the station house, but Buntz catches her stealing cocaine from the property room and the bust allows Hill Street to meet their quota.

Seven members of a family are murdered in their home; Goldblume reluctantly tries to use a former member of the Blood as an informant, but the head of the Blood immediately identifies him as a "snitch"; Belker lucks into the identity of the murderers when he busts a low-level drug dealer who met the murderers immediately after the crime; Renko has both urine and vomit thrown upon him during his patrol, but his day improves when he delivers a baby girl and the parents name the child after him (Andrea); at the end of the episode, the head of the Blood is found dead and Goldblume's informant is suspected of the homicide.

A jealous Renko confronts his wife about her relationship with her business partner in her cookie-making company, and at the end of the episode, he sleeps with a classmate from night school; a Hill Street officer with limited fluency in Spanish shoots an innocent Hispanic when he doesn't understand what he's saying; Ray Calletano, now representing the Latin-American Coalition, threatens a lawsuit on the victim's behalf - until he finds out that Furillo would bear the blame; Flaherty's romantic involvement with Russo begins to interfere with work, resulting in Bates dressing down both of them after she is slashed due to Flaherty's inattentiveness; Goldblume finds his informant, who did indeed kill the head of the Blood, and is forced to kill him when he turns a gun on him; Belker, acting on a tip from a snitch, buys stolen credit cards, but is shot in his car in the final scene. Rene Enriquez (Ray Calletano) returns to the opening credits for this episode only.

Belker survives the shooting and is rushed to the hospital with a bullet near his spine; Buntz brutalizes Belker's snitch to get the name of Belker's contact, who refuses to provide any information and is later found dead; Furillo, who is blaming himself for Belker's injury, takes Buntz off the case, but Buntz continues investigating anyway and finds a District Attorney's investigator with connections to the stolen credit cards, Belker's contact and Belker himself; the investigator kills himself when Buntz, LaRue, and Washington arrive to question him; Renko discovers the hard way that the night school classmate with whom he had his one-night stand is a hooker---who tries to blackmail him, and he and Daryl Ann part after he confesses to sleeping with his ex-classmate, nullifying the woman's blackmail attempt, and Daryl Ann confesses her own affair with her business partner; Flaherty and Russo also part company after a drugged Russo calls for another man; Sergeant Hunter is restored to his former rank of Lieutenant and resumes command of the EAT; Belker moves his hands and feet in his hospital bed, relieving his wife, Robin, and his colleagues. Robert Prosky (Stan Jablonski) returns to the opening credits for this episode and the next.

The city is full of stunts after a radio station challenges citizens to commit "outrageous acts"; this includes gang members (one played by Cuba Gooding Jr) releasing a live piglet into the Hill Street squad room; with Hunter resuming command of the EAT, Bates resumes Desk Sergeant duties; Hill and Renko are assigned a new unit (2403), state of the art, and computer-controlled - with disastrous results, which include Renko inadvertently winning the radio competition when he accidentally causes the unit's computer to disrupt traffic lights along a fifty-block length of Dekker Avenue; Belker returns to the precinct intending to ease back into his work; Renko forgives Darryl Ann, who is still uncertain about forgiving Renko just yet; Jablonski's badge is found on an arrested prostitute, and Belker gives it back to Jablonski, who voices frustration that he could not prevent the theft; while investigating a possible Indian burial mound in a house's basement, Hunter and a friend are caught in a cave-in. Don Cheadle plays Darius Milton.

A famous American football player (Keenen Ivory Wayans) is arrested for soliciting, but his high-powered attorney and Chief Daniels intervene to reduce the charges and protect his reputation; given 20-1 odds against beating the department's four-time marksmanship champion, LaRue's syndicate bets $400 on Buntz, but Buntz loses by two points in the final round of competition; Furillo backs a loan for his brother, whose construction company is in debt after missing a completion date on a project; fears grow as Lieutenant Hunter fails to report for duty, and his former paramour Prunella returns from Samoa to search for him. Unusually, this episode begins without the usual on-screen opening time check, though Furillo quotes the time as 6:30 A.M. after examining his own bedside alarm clock.

Lieutenant Hunter is found alive after 11 days, and it is discovered that his friend had been dead for a week, and - under a pact with Hunter - Hunter ate a portion of him to stay alive; Hunter discusses this with Furillo (who advises him not to discuss it) and Prunella (who leaves him); Lieutenant Buntz is accused of stealing a kilogram of cocaine from the suitcase in Episode 1; a box containing $17,000 (actually belonging to his late friend Donahue) is found in Buntz's apartment, leading Internal Affairs to suspend him; Grace Gardner returns to the precinct after having left the convent after finding her "concept of love" incompatible with chastity; she now works with a condom-distribution company and informs Furillo that the company installs machines free for law enforcement agencies, as "Our motto is the same as yours: To protect and serve."[9] The sister of Jesus Martinez is apparently kidnapped shortly before her wedding to a member of the Gypsy Boys; when it is discovered that she actually loves a member of the Shamrocks, Jesus gives his blessing for them to be married; LaRue narrowly escapes death and rides a rollercoaster of emotion, finally breaking down sobbing in Washington's arms. Bryan Cranston plays Buntz's PBA counsellor.

The final episode. The Hill Street stationhouse is gutted by fire, though the basic structure still stands; Lieutenant Buntz, Captain Furillo, and Sidney Thurston investigate the case against Buntz and uncover a plot to frame Buntz, in which Internal Affairs investigator Lieutenant Shipman is implicated; fearing that Shipman will flee prosecution, Buntz takes matters into his own hands and holds Shipman at gunpoint, and both are arrested: Shipman for the cover-up and Buntz for carrying a gun while suspended; when Chief Daniels announces publicly that he intends to have Buntz fired, Buntz punches the Chief in the face (a development that TV critic Ron Miller called "marvelous" in a column bidding farewell to the series); Goldblume works with a Division investigator and a prostitute to locate and arrest a notorious serial killer; Belker finally addresses his late mother's possessions; Sergeant Bates and Sal the plumber finally have dinner together, with perhaps a hint at a relationship developing; Buntz leaves the fire-damaged station in the final scene, but the last words are spoken by a constant, but low-profile, character ? the night shift desk sergeant (Lawrence Tierney), who answers a ringing telephone, and states the final words of the series: "Hill Street". The Buntz plot set up the spinoff series Beverly Hills Buntz.