This article offers a framework to model the epistemological terrain of the circulation and regulation of knowledge in late-period Soviet society. It proposes that secrecy and openness operated in a mutually constitutive “social map of knowledge” that was constantly shifting due to the inability to maintain secrecy as a stable category. Investigating the domain of Soviet science, this article sheds light on the work of institutions such as Glavlit, the state censorship authority, which supported the state’s goal to maintain the contours of secrecy as a static category by repeatedly issuing edicts and restructuring the apparatus of secrecy in the face of constant and destabilizing social, cultural, and technological pressures. This stable but volatile condition encouraged a common language of “speaking in secret” that cut across the Soviet social order. The “social map of knowledge” was one with high peaks, where valuable knowledge was placed in the hands of those with power, even as these peaks were under intense pressure to collapse from a parallel market of speculation marked by rumor, suspicion, and conspiracy theories. This form of “stable volatility” became impossible to maintain in the 1980s, when a deluge of information flooded Soviet society.