"How to Forget a Terror Which Became Permanent" is a film essay that explores the reasoning and motivations inside the regime which authored 1968’s Tlatelolco massacre in Mexico City, the film portrays the creation of the foundational fear that defined the relationship between Mexico's civil society and its authoritarian government. The roles of the presidential administration, the media, the international community and civil society are illustrated by the use of archival footage and on screen intertitles.