Psychological drama directed by Kyle Patrick Alvarez. In 1971, Professor of Psychology at Stanford University Philip Zimbardo (Billy Crudup) conducts an experiment in which 24 students are randomly assigned roles as prisoners or guards in a mock prison setting. The two-week test, designed to assess whether personality traits of prisoners and guards are the direct cause of negative behaviour between them, quickly gets out of hand. With attitudes becoming increasingly abusive, Zimbardo is forced to step in and put a stop to proceedings after only six days.