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.