A prison in an isolated island is run by spineless and equally sadistic Dr. Carlos Costaa. In fact, he is a killer who murdered the actual doctor of that name, whose name he then assumed. Assisting him is a monocled lesbian woman known only as The Wardress who regulates the prison with an iron fist - for example, via chaining them naked to a wall just out of reach of food, or placing them naked on a wire-frame bed where they receive electric shocks. She reads Nazi volumes such as Albert Speer's history of the Third Reich as leisure reading. Due to these torturing several prisoners in the past have died. The current authorities in charge of the prison have concealed this by claiming these prisoners died of heart failure. Maria is sentenced to life in prison for the murder of her sexually abusive father. Upon her arrival at the prison, she meets this cold-blooded, sadistic wardress and Dr. Costa. Some time later Maria organizes a plan to rebel and escape.