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.

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.

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 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.

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.

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.

McManus calls a superficial truce between Redding and Morales. Basil finally sees his wife, but Hughes ends up spoiling their happiness. Meanwhile, Cyril's latest outburst proves to be the last straw.

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.