During the TV premiere of the detective story by Petr Tarantík (Miroslav Machácek) called Case for Three Murderers, a popular actor dies in the midst of live broadcasting, in front of the eyes of millions of TV viewers, the whole crew and the rest of the cast. It is soon discovered that he was murdered - somebody intentionally connected the armchair in which the actor was seated to electricity and his weak heart failed. In the course of the investigation, Captain Suda (Radovan Lukavský) introduces himself to the facts connected with the filming as well as with the relations between the people involved, paying special attention to those who had "reason" to kill the actor.