In 1971, psychologist Philip Zimbardo turned a Stanford University basement into a mock prison and asked ordinary student volunteers to play guards and prisoners for two weeks. The film revisits that study through Zimbardo himself along with collaborators Craig Haney, Curt Banks, and Carlo Prescott, tracing how quickly the assigned roles took over: guards escalating into humiliation and control, prisoners breaking down within days. Archival photographs and recordings from the original experiment sit alongside present-day interviews reflecting on why the study was shut down early and what it revealed about obedience, power, and institutional pressure. The film treats the Stanford Prison Experiment not as a curiosity but as a case study in how situations, more than individual character, can drive people toward cruelty. It also weighs the criticism the study has faced over the decades, from questions about coaching and consent to its lasting influence on how psychologists think about authority and human behavior.