Budapest, Hungary, Christmas 1957. The state, insecure after the defeated revolution of 1956 and increasingly put under the influence of a renewed Stalinist atmosphere, has decreed that all security officials must pass an exam to verify their loyalty. But to be actually effective in a shadowy world where suspicion and secrets reign, the subjects must be unaware that they are being tested.

During the Cold War, the secret service of Kádár began a more dangerous state security game than ever before.