The film is about the experiences of survivors of the Khmer Rouge's regime in Cambodia, specifically those who were held at the Security Prison 21, also known as S21. The director, Rithy Panh, brings back two survivors, including painter Vann Nath, who was spared execution by chance, to discuss their time in the prison. The former guards, some as young as 12, recount their atrocities with varying levels of remorse, while the prisoners would often confess to anything to avoid torture, ultimately leading to their deaths.
S21: The Khmer Rouge Killing Machine
The film is set at the Tuol Sleng Genocide Museum in Phnom Penh, Cambodia, a former notorious prison where prisoners and former guards share their experiences in a powerful documentary.