In 1971, psychological professor Philip Zimbardo conducted an experiment where eighteen male students participated in a 14-day prison simulation where they either became a prisoner or guard.
In the mock prison, the roles are assigned somewhat arbitrarily, but the results are almost immediate.
The controversial real-life experiment became revealing in many of the worst ways, providing a harrowing, haunting framework through which director Kyle Patrick Alvarez makes a chilling, relentless drama based on this true story.