A documentary about the re-enactment of the Stanford Prison Experiment - a famous psychological experiment studying human behaviour in prison conditions, conducted in 1971 by Professor Philip Zimbardo at Stanford University in California. In early 2005 the artistic radical Artur Zmijewski took the risk of reconstructing Professor Zimbardo's experiment in Warsaw. He tried to recreate precisely the architecture of the simulated prison and its rules. Seven "prisoners" and nine "guards" were selected in a procedure aimed at eliminating mentally unstable candidates. They were offered $40 a day for their role in the experiment. The rooms were equipped with one-way mirrors, and the course of the experiment was filmed by five man-operated cameras and several night vision-enabled industrial TV cameras. In the process, Zmijewski pierces through societal masks and travels to the heart of mankind, where it is still dark.