The time of action is the end of the last century. Location - St. Petersburg. The head of the detective police, Ivan Dmitrievich Putilin, is investigating the murder of a high-ranking diplomat - an Austrian military agent. The failure of the investigation could threaten a major international conflict. Suspicion falls on several people, including the diplomat's mistress and her deceived husband. In the end, the murder will be solved from a completely unexpected side, and Ivan Putilin's track record will be replenished with a new completed case. There will be many more such cases - there is a whole series of novels by Leonid Yuzefovich about the famous Russian detective ahead.