A detective story revolving around an ancient treasure from the ninth century, believed to have been destroyed during World War II, takes place in an archaeological environment. Its main character is, alongside Captain Exner, who is investigating a strange murder committed on the premises of a scientific institute, a young student at the Academy of Sciences and Arts of the Slovak Republic, Kamila Housková, who discovers that the treasure was not destroyed, but most likely stolen. The bright girl continues her search for the treasure against Captain Exner's will and leads the investigators to a trail that proves the connection between the lost treasure and the murdered woman...

At the center of the crime story is the very large Kremp family, living in the family villa with other relatives and a subtenant. The parents had four adult children, two sons and two daughters, one of whom recently died. The investigation focuses on the recent death of their son Jan. The young man was considered the family "fool", whom no one except his mother liked, because he played various mischievous tricks on everyone. However, his death, as Captain Exner investigates, was not an unfortunate accident, but a murder. Who could have been interested in his death? Was the murderer someone from the immediate family? Captain Exner is looking for a motive...

Vera, wife of the plumber Simandl (Josef Somr), is found murdered in the cinema next to the IDOC (Information and Documentation) agency where she worked. Police captain Marha (Frantisek Nemec), who is leading the investigation, is informed by Simandl that on the day of the murder Vera promised to bring home fifty thousand crowns to buy a car. Marha's primary suspects are the three men working at the agency: deputy editor-in-chief Brandl (Jirí Pleskot) and editors Pernata (Eduard Cupák) and Remes (Ludek Munzar, and of course also Simandl.

Captain Exner solves another detective mystery - this time while he's on vacation. The most elegant of Czech crime novelists has chosen a quiet town called Opolná as his place of well-deserved rest. But just as he arrives, the local shoemaker Rambousek, a famous (and wealthy) naive painter, is murdered.