Sisters Olga and Svetlana Martynovs quarrel over the conditions of the funeral of their deceased mother Polina - Olga insists on the funeral of her mother with her beloved ring, and Svetlana wants to carry out cremation according to the agreement drawn up by Polina shortly before her death. However, the ring disappeared without a trace, and Polina was cremated. Soon Olga is found dead, and the examination establishes that the cause of death is a drug overdose. After interrogating Svetlana, investigators learn that the ring was very valuable. The deceased Olga suspected the previously convicted groom of her sister Khromov, but he turns out to be not involved in either the theft of the ring or the murder, but someone clearly wants to set him up ...

The famous cardiac surgeon Leonid Feldman was shot dead in a restaurant toilet. Suspicion falls on the ex-wife of the murdered Veronica, who accused him of harassing their young daughter Sonya, and then on Veronica's sister Serafima Linkova. However, Sonya denies the accusations against her father. Upon learning of this, Seraphima leads the investigation to the real killer ...