The intelligence officer Emil Boev is tracking a group of drug addicts, who were recruited by a foreign intelligence office. Among them is Boyan, the son of Emil's dead comrade. He should help the boy. He includes Boyan in the counterintelligence action plan. The faith of the young people is sealed - they should be eliminated as unwanted witnesses. They are given hot doses. Boev and Boyan discover the plot, but it is too late for some of the people. The deadly needle gets in the hand of the girl that Boyan loves. The foreign resident is captured. There is hardly anyone at the grave of the girl. Only Boev and Boyan come and listen the requiem.

Marinov is found dead, and suspects include Baev, Dimov, and Zhana. The Inspector, who deals with life’s dark side, investigates. Despite his loneliness, he shows compassion, especially towards Zhana. Ultimately, he concludes Marinov committed suicide and demonstrates that people can embrace higher morality. Based on the detective book by Bogomil Raynov.