The head of a Prague clinic, Professor Trojan (Karel Höger), lives a quiet life in his flat in the Lesser Town, one of Prague's historical and oldest boroughs. His son Petr (Josef Abrhám) is also a doctor, but to his father's displeasure he has moved to the Moravian city of Brno with his wife Eva (Jana Brejchová), a singer at the start of her career. Trojan has just one friend, the retired judge Karel Seda (Martin Ruzek). One day someone poisons Trojan's cat. On the same day someone shoots at the professor through the window of his flat. The professor at first shrugs off the incidents, but then he starts to be afraid. He thinks hard about his relationships at work and in the family.