In the beginning of 1968, a lieutenant of the KGB, Yuri Volkov, is among a group of officers transferred to Prague to teach advanced agent operations. The central administration is rather worried by a growing reformist mood in the new Czechoslovak party leader Dubček. The young, but promising specialist Volkov takes to the work like mad. He succeeds in picking up the trail of a dissident organization, which is suspected of undermining the ideological foundations of the Soviet System. The investigation is progressing quite well, and Volkov is already dreaming about concluding such an important affair. Is he going to be lucky, get a new epaulette maybe? An incidental encounter with one of his students, a woman from Paris, at first looks like an accident, but it suddenly causes him to make adjustments in the course of his investigation.