When East Germany began building the Berlin Wall on August 13, 1961, the country's secret police saw opportunity rather than crisis. This film traces how the Stasi, under Erich Mielke, turned the Wall into the center of its operations over the following decades, recruiting agents specifically to guard, surveil, and seal the border. It follows the escalation of tunnels, informants, and watchtowers built to stop East Germans from crossing, and the bureaucratic machine that grew around a single structure until it employed thousands of officers by the time the Wall fell in 1989. Archival footage and period photographs carry much of the story, showing checkpoints, patrols, and the no-man's-land strip known as the death zone, alongside accounts of how ordinary surveillance became institutionalized paranoia. The film treats the Wall less as a barrier than as an engine that fed an entire secret police apparatus, and traces what happened to that apparatus once the concrete finally came down.