The Dirección Federal de Seguridad (Federal Security Directorate) is Mexico’s premier intelligence and internal security agency, established in 1947 and continuing to operate in the mid-1960s. Tasked with counterintelligence, political surveillance, and counterterrorism, the DFS is more preoccupied with being de facto a clandestine enforcer of Mexico’s ruling elite, suppressing dissent and infiltrating opposition movements such as the Mexican Student Movement of 1968. Officially a bulwark against Soviet espionage and foreign subversion, it became notorious for its role in suppressing left-wing activists, labour unions, and student movements, employing brutal tactics ranging from psychological warfare to extrajudicial killings. The agency’s unchecked power, deep ties to organised crime, and involvement in global Cold War espionage make it a feared and controversial institution, symbolising the dark underbelly of Mexico’s political landscape.