This episodic story is set in So Paulo's notorious jail known as Carandiru, one of Latin America's largest and most violent prison systems. The doctor (Luiz Carlos Vasconcelos) is an oncologist who arrives in the jail as a volunteer to test the prisoners for HIV infection. Seeing the disease, overcrowding, and rampant circulation of drugs, the doctor realizes much of the prison is controlled by the inmates. They decorate their cells and have an established pecking order. The strong inhabit messy individual suites, and the weak are jammed together, as many as sixteen sharing a 100-square-foot (9.3 m2) cell. Several narratives develop in the film: the attempted murder of Peixeira (Milhem Cortaz), the solitary confinement of Chico (Milton Gonalves), and the romance between Lady Di (Rodrigo Santoro) and Too Bad (Gero Camilo). The doctor establishes a routine and comes to see the prisoners as survivors. The picture ends with a violent prison riot that historically took place on October 2, 1992. The repression of the riot became known as the Carandiru Massacre.