When the Moscow hotel “Intourist” is being demolished, workers find an audio cassette with a recording of a strange conversation under the floor and take it to the FSB. Analysis shows it is a recording of a recruitment conversation that took place 30 years ago. A young lieutenant is looking for the recruited spy—his investigation intertwines with the adventures of diggers in mysterious Moscow undergrounds, with the work of the CIA searching for ways to obtain Russia’s state secrets, and with the daily life of tiny-scale prostitutes… In the end, the lieutenant finds a spy device installed at one of the training grounds in the seventies and makes an arrest of a high-ranking military official. But is it the same person who was recruited three decades ago?