This unsettling fact-based drama reproduces the notorious, still controversial psychology experiment from 1971 in which a bunch of 24 Californian university students volunteered to take part in a study into prison life. A flip of a coin decided who would be mock guards and who prisoners, but the role-playing soon got alarmingly out of hand.

Ezra Miller and Michael Angarano stand out among the students, while Billy Crudup plays the tunnel-visioned academic in charge, Philip Zimbardo. The film is tough going in places but offers a chilling study into the psychology of authority and the abuse of power.