A student of the architectural institute was killed on the square of the Leningradsky railway station. The attention of investigators is attracted by a famous architect, whose work was fond of the murdered. It turns out that the architect is married to three women at once, one of whom is pregnant, and the student is the architect's illegitimate son ...

Two men were killed - Ivan Kirillov, who was wanted in the case of a large embezzlement of depositors' money, and his own son Leonid ...

Businessman Mikhail Solodovnik was killed. All members of his family are under suspicion. Petrovskaya and Loginov inspect the apartment of his ex-wife and discover potent drugs ...