Late July 1988, the Islamic Republic of Iran suddenly locked down its prisons where thousands of political prisoners were serving their sentences. For five months, families desperately searched for news about their imprisoned loved ones. When finally they were summoned to prison, they were given a bag and told that their prisoner had been executed -- no explanation, no last will, no body, no burial location. To this day, no Islamic Republic official has assumed responsibility. To this day, talking about it is a taboo. But thanks to the brave survivors and family members who have come forward to tell their stories, the secret is out. The world can now learn about the 1988 prison massacre in Iran's prisons, unique in the known history of state crimes.