Director Albert Veselovsky turns to private detective Tatyana Ivanova with a request to help his friend Korotkov. A friend was arrested after being caught with a knife over the corpse of a neighbor. Korotkov was always famous for his quarrelsome character. On the day of the murder, he had just publicly quarreled with his murdered neighbor. The victim - Natalya Belokopytova - that morning, in turn, had a serious quarrel with her husband, whose life she had been poisoning for many years. However, not only him. Thus, besides Korotkov, the husband of the brawler is suspected, but both reliable versions of Tatyana are collapsing one after another, like houses of cards...