Augustus Hill, the series' narrator, introduces the audience to Cell Block 5 of the Oswald Maximum Security Penitentiary ("Oz").

The violence of Oz is demonstrated right away as new inmate Miguel Alvarez is shanked before even being brought inside, horrifying fellow arrival Tobias Beecher.

Correctional officer Diane Whittlesey assigns the arrivals to their "sponsors", veteran prisoners who at least nominally look after them and ensure they integrate appropriately.

Groves is assigned the kindly Bob Rebadow; Markstrom's sponsor is Jefferson Keane, a fellow "Homeboy"; and Beecher is given Italian-American mobster Dino Ortolani.

The following morning, McManus complains about the draconian laws passed by Governor James Devlin, saying that banning cigarettes will make the inmates uncooperative.

Later, he is furious to find out that Irish-American hoodlum Ryan O'Reily, the victim of the assault which landed Ortolani in Oz, is coming to the same prison.

As he is sleeping, a bribed guard lets one of Keane's henchmen, Johnny Post, pour lighter fluid on Ortolani and set him on fire.

Creator Tom Fontana pitched the idea of Oz to the cable channel HBO after years of dissatisfaction working within the constraints of network television and their expression-limiting censoring requirements.

Fontana felt extremely liberated and satisfied writing for Oz, developing graphic scenes and breaking taboos with which, he says, he would have never gotten away in network TV.