Drama series set in an urban prison that is divided into two distinct sections. The first is old and foreboding while the second, "Emerald City," is brighter and supervised by someone who believes that every prisoner is capable of rehabilitation. Em City is an experimental unit of the Oswald Maximum Security Prison (OZ). Despite the modern facilities and an emphasis on rehabilitation over retribution, survival remains a top priority. Each episode focuses on a specific theme, touching on everything from religion to sex and drugs to capital punishment, as it follows the day-to-day action with the prison.