Cambodian director Rithy Panh's "work of remembrance" revisits the S21 detention centre in Phnom Penh. Here, under Pol Pot's rule, thousands were tortured by Khmer Rouge followers.
Reuniting two of S21's surviving inmates with the guards responsible for their abuse, documentary-maker Panh focuses on the details of the genocide. It's tough viewing and a thoughtful attempt to come to terms with a country's traumatic past.