In the 'Emerald City' experimental unit of Oswald State Penitentiary, we meet some of the diverse inmates who exist in a pecking order of Gangbangers, Latinos, Muslims, Westies, Aryans and Wiseguys.

With Schibetta and the prison brass in a race to uncover Ortolani's killer (for very different reasons), we see how inmates react to visits both from their wives and (in one case) family members who are also in prison.

Friction is growing in the wake of two deaths so Said, Wiseguy leader Schibetta and Gangbanger Jefferson Keane are brought together by Warden Glynn, who tells them to keep their boys quiet or else he'll lock the prison down.

Governor Devlin has reinstated capital punishment in the state--and the first Oz prisoner scheduled to die is Jefferson Keane, who killed a Latino in their skirmish. Before he's executed, Keane donates a kidney to his ailing sister.

The infiltration of drugs into Oz has reached scary levels, and the efforts of McManus and Glynn to find out who's smuggling backfire in a deadly way. Despite a lockdown, drugs continue to trickle in--and the blame shifts to corrupt officials.

Ricardo is discovered to suffer from Alzheimer's; Beecher flips out and sends Schillinger to the hospital; mob boss Schibetta develops stomach problems thanks to some ground glass; and Said has a heart attack.

A recovered Said ostracizes Huseni Mershah for turning his back on him when he was dying--and orders all the Muslims to cast him out. Impressed by Said's power, Groves decides to kill Glynn in his honor, but ends up stabbing an officer by mistake.

After a visit with his sons, Schillinger realizes he needs to get paroled. He convinces McManus to let him return to Em City with the condition that he leaves Beecher alone. Beecher comes out of the hole hell-bent on making sure Schillinger doesn't get paroled. McManus gets wind of Wittlesey and Ross' contraband operation and orders her to shut it down. Ross makes it very clear to her that this will not happen. The Muslims meet and discuss how the riot will begin. However, two rednecks beat them to it by fighting over a game of checkers. This causes all the inmates to get involved and they quickly overpower the COs who are trying to break it up. Said orders the Muslims to get out and seize control. Said pulls out the gun he acquired from a rookie CO and fires a shot into the air, causing Em City to quiet down. Said meets with Ross, Adebisi, O'Reily and Alvarez to discuss strategy and demands. Said agrees to let O'Reily, Ross and Adebisi control the main gate and Alvarez will control the hostages. Dobbins was seriously injured during the initial uprising and Hill convinces Vayhue to step up and help. Vayhue and Dobbins leave Em City only to be beaten up by SORT. The hostages require medical attention, so Alvarez and Said vote in favor of a doctor. However, Adedisi, Ross and O'Reily vote no. Governor Devlin orders the National Guard to surround the prison and take it back, but Glynn and McManus think they should see the demands first. McManus volunteers, to Devlin's disgust, to enter Em City to deliver food and check on the hostages. He tries to get COs Armstrong, Mineo and Wittlesey free in exchange for himself. He gets Armstrong and Mineo released, due to their injuries but Wittlesey has to stay. After reading the demands, Glynn realizes that the prisoners are being quite reasonable, however Devlin orders the National Guard and SORT to re-take Em City anyway. Meanwhile Ross' men and Adebisi's are constantly fighting, so Said tells O'Reily to switch Ross' men with Alvarez's at the front gate. A short tie later, Adebisi's men start to fiend due to the depletion of heroin, resulting in a major skirmish. Just as that situation is resolved and the Homeboys are tied up, the lights go out. Said realizes the situation and orders Ross to bring out the hostages as a front line of defense. Soon tear gas is thrown into Em City, then a tractor breaks through the barricade and gunfire rings out in Em City.

Season Two premiere. In the aftermath of the riot that killed six inmates and two officers, Oz is locked down, and Emerald City prisoners are sent either to solitary or gen pop. A special committee is appointed to investigate the riot.

Ten months after the riot, Em City is reopened. A recovered McManus creates a council of group representatives to keep order, and initiates classes to help inmates get high-school equivalency diplomas.

Alvarez knows who raped Glynn's daughter, but refuses to tell the warden. Wangler is making progress at school, but his cellmate, Adebisi, isn't a fan of higher education. When Hill's judge is convicted of accepting bribes, Said takes up Hill's case.

Augustus Hill's appeal is denied, despite the efforts of Said, who has better luck with Poet's poems. Meanwhile, O'Reily survives his lumpectomy, and now focuses his attention on Dr. Nathan.

With their enmity at a boiling point, Adebisi poisons Schibetta--but not fatally. Now that his brother has turned himself in for murder, Glynn no longer owes Schibetta any favors.

Schillinger attempts to enlist Said to get him out of jail. Recovered from being poisoned, Schibetta is brutalized by Adebisi, losing 'control' of Oz. Meanwhile, Alvarez is bumped out of the Latino power seat by Raoul Hernandez, a.k.a. El Cid.

Cyril O'Reily, Ryan's brother, is imprisoned and falls under Schillinger's control. Ryan tries to get him away into Em City, but Cyril winds up in the hole. El Cid tells Alvarez there's only way he can 'stay in the game.'

In the Season Two finale, Wittlesey is transferred to general population and replaced by Karl Metzger, a Nazi. Mack and another Aryan try to escape through Busmalis and Rebadow's hole. Hill gets the idea of escaping Oz by hiding in a coffin.

In the Season Three premiere, Beecher is still in the hospital after Schillinger and Keller broke his bones, Alvarez is still in solitary for blinding Rivera, Adebisi is back in the kitchen and McManus starts dating a newly arrived CO.

No one knows who killed Metzger. Meanwhile, McManus hires his friend Sean Murphy as a C.O. and he launches a boxing program. Hill faces a dilemma when a new inmate reveals a terrible crime. Adebisi sticks Nappa with an AIDS-infested hypodermic.

In the boxing program, O'Reily spikes Robson's spritzer bottle before his bout with Cyril. Rebadow's mother tries to persuade him to meet his son and grandson. Meanwhile, Nappa finds out he's HIV-positive and is moved to Cell Block E.

O'Reily and Keller plot to take care of Andrew. McManus is forced by prison brass to settle Howell's sexual-harassment suit. Hanlon's murder convictions get overturned and he's allowed back in the general population--where he finds new troubles.

Wangler 'finds out' his wife and her lover were murdered execution-style. Meanwhile, Poet and Pierce get burned by Hernandez, Ricardo and Guerra. Lockdown ensues, and Wangler finds himself vulnerable--and in a cell with Adebisi.

With Cyril scheduled to box Pancamo, O'Reily plans to use his spray-bottle trick, but first he must deal with Cudney. Alvarez sees the photos of Rivera's gouged-out eyes and goes nuts. New roommate Nat Ginzburg offers to be Nappa's secretary.

Adebisi accuses McManus of sexually harassing Wangler. Bellinger meets with McManus and requests execution by hanging. Just one problem: she's pregnant.

Brace yourself for the explosive Season Three finale! As the new millennium approaches, things are heating up in Em City as racial tensions mount. Glynn fires Hughes, but before leaving, Hughes delivers a millennium gift to Adebisi: a gun.

Season Four premiere. The world of Oz--an experimental prison within a prison known as the Emerald City--reopens its doors with the inmates still on a 24-hour lockdown and prison officials struggling to end the hostilities.

The African-American inmates point the finger at McManus for letting Em City get out of hand. After that and his recent erratic behavior, McManus gets the ax from Glynn. Mobay's cover is almost blown.

Glynn learns from Adebisi that he was given the gun by former C.O. Hughes. Morales enlists Rebadow's help in taking Hernandez's place in the drug ring run by Adebisi and Pancamo. Mobay finds himself in a dangerous position.

New inmate Burr Reading arrives, ready to take charge of the African-American drug scene. Dr. Nathan returns to Em City, and finds the biggest adjustment is dealing with her feelings for O'Reily. Tidd tries to strike up a deal with Schillinger.

Morales looks to pit the Chinese against Redding. Alvarez offers Glynn his services as an informant as a way out of solitary. Dr. Nathan announces that Em City inmates will be selected to test a trial drug that could reduce their time behind bars.

O'Reily regrets getting Cyril involved with the trial drug when it starts taking effect. Meanwhile, Giles' request for an unusual execution creates controversy and the Chinese refugees are deported...but not before plotting revenge on Morales.

McManus can't turn his back on White. Beecher tells the parents of the girl he killed that he's up for parole. Howell tries to blackmail O'Reily so she can get to Cyril, but he throws her for a loop--and then O'Reily is thrown himself by a secret.

In the Season Four finale, Hill discovers where his true allegiances lie in Oz. Redding's plot to use the Colonel against Morales has an unexpected outcome. Beecher's agony about his parole hearing leads to a shocking season climax.

In its fifth season premiere, Oz re-opens in the wake of major renovations that had to be completed following a gas explosion.

McManus thinks White may reform if he spends quality time with Said; Alvarez offers Guerra a unique solution to their dispute; O'Reily's mother, Suzanne Fitzgerald, begins a community service term teaching music at Oz.

Brass wants to know who cut his tendon; Redding and Morales form another uneasy alliance; Rev. Cloutier's mysterious influence over his followers grows more intriguing; and Keller returns to Oz, only to be hit with an ID from an old murder charge.

Penders, Hill and Alvarez are given a chance to train seeing-eye dogs; Martinez gives Brass a 'cocktail' he definitely didn't order; the love triangle between Beecher, McClain and Keller becomes more complicated.

Robson stirs up problems between White and Said. Meanwhile, Pancamo's illness might save some work for his enemies, Schillinger makes a friendly but suspicious overture towards Beecher, and Morales seeks revenge on his sister's abusive husband.

As Cyril's trial gets off to an inauspiciously cold start, tensions between Mukada and Kirk come to a boil. Also, a priest named Meehan lands in Oz while White and Said turn over a new leaf in their relationship.

Hill's recovery leads to renewed friction between Redding and Morales, Alvarez gets his wish as the 'Man's Best Friend' program is finished and Meehan presents some revolutionary ideas to help Cyril.

In the Season Five finale, Robson goes to extremes to remedy his gum dilemma, Meanwhile, McManus struggles with personal turmoil over his decision to stay at Oz and Rebadow deals with his grandson's fate.

In the Season Six premiere, Alvarez and Schillinger are let out of solitary and placed back in general population. Meanwhile, a mourning Rebadow's spirits get a lift when he is transferred to the library and meets the new librarian, Stella Coffo.

The unexpected arrival of Mayor Loewen at Oz spurs an ironic turn involving Schillinger and Beecher. Meanwhile, Dr. Nathan discovers why solitary inmates are getting sick. A new business plan within Oz inspires Redding.

Tobias learns who killed his father before being released from prison. Cyril begins shock therapy while receiving an execution date. Said is allowed to start his own company.

Glynn receives mixed news on the toxic-poisoning problem. Meanwhile, Rebadow's relationship with the new librarian Stella hits a snag, Keller and Beecher work out an agreement, and Robson finally gets some redemption.

Arif and the others have trouble getting Augustus' book published. Tobias confesses to Chris he's started dating someone on the outside.

New inmate Idzik faces his enemies and requests a transfer. Meanwhile, the Loewen case grows increasingly complicated, the Muslims run into business trouble, and the inmate population comes together to support the O'Reilys.

Three new inmates arrive at Oz, one of whom is particularly close to the O'Reily clan. Meanwhile, the Keller-Beecher-Schillinger triangle gets even more pointed, and an awards banquet ends in a fateful discovery.

Querns is appointed the new warden of Oz. Brass attempts to get famous for a day. Tim tries to change the mindset of Said's murderer. Cyril is finally executed. Keller brings Tobias back to Oz for good.

Hill's recovery leads to renewed friction between Redding and Morales, Alvarez gets his wish as the 'Man's Best Friend' program is finished and Meehan presents some revolutionary ideas to help Cyril.

No one knows who killed Metzger. Meanwhile, McManus hires his friend Sean Murphy as a C.O. and he launches a boxing program. Hill faces a dilemma when a new inmate reveals a terrible crime. Adebisi sticks Nappa with an AIDS-infested hypodermic.

With Schibetta and the prison brass in a race to uncover Ortolani's killer (for very different reasons), we see how inmates react to visits both from their wives and (in one case) family members who are also in prison.

McManus thinks White may reform if he spends quality time with Said; Alvarez offers Guerra a unique solution to their dispute; O'Reily's mother, Suzanne Fitzgerald, begins a community service term teaching music at Oz.

Alvarez knows who raped Glynn's daughter, but refuses to tell the warden. Wangler is making progress at school, but his cellmate, Adebisi, isn't a fan of higher education. When Hill's judge is convicted of accepting bribes, Said takes up Hill's case.

Glynn receives mixed news on the toxic-poisoning problem. Meanwhile, Rebadow's relationship with the new librarian Stella hits a snag, Keller and Beecher work out an agreement, and Robson finally gets some redemption.

Friction is growing in the wake of two deaths so Said, Wiseguy leader Schibetta and Gangbanger Jefferson Keane are brought together by Warden Glynn, who tells them to keep their boys quiet or else he'll lock the prison down.

New inmate Burr Reading arrives, ready to take charge of the African-American drug scene. Dr. Nathan returns to Em City, and finds the biggest adjustment is dealing with her feelings for O'Reily. Tidd tries to strike up a deal with Schillinger.

Ten months after the riot, Em City is reopened. A recovered McManus creates a council of group representatives to keep order, and initiates classes to help inmates get high-school equivalency diplomas.

Three new inmates arrive at Oz, one of whom is particularly close to the O'Reily clan. Meanwhile, the Keller-Beecher-Schillinger triangle gets even more pointed, and an awards banquet ends in a fateful discovery.