Tarek Fahd (Moritz Bleibtreu) participates with 19 other candidates in a prison simulation experiment for two weeks. The candidates are selected by a computer to be either prisoner or guard. The experiment begins smoothly, but quickly deteriorates as the guards develop authoritarian tendencies. Prof. Klaus Thon (Edgar Selge), perceiving the deterioration as standard psychological reactions, refuses to end the experiment, despite the protests of his assistant, Dr. Jutta Grimm (Andrea Sawatzki). As time progresses, the guards go to great lengths to conceal their actions and keep the experiment running, and the prisoners resist as best they can.