The village of Seefeld Tyrol has just been the scene of a tragedy Wollmer, owner of the sawmill and of most of the country, a hard and rapacious man, has just been assassinated Everyone hated him and Friedrich, the commissioner in charge of the investigation, will have to work hard to find the culprit Arrives Wollmers widow, who was going through a divorce A foreman, Franz, offers to help him But she receives anonymous letters offering her the name of the murderer for money Franz has strange reactions, and so does Klara, the hoteliers daughter, who takes a dim view of his intimacy with Mrs Wollmer Harassed by the sound of a typewriter, Mrs Wollmer gradually loses control of her nerves She accuses Franz and, in a movement of hatred, throws him into a ravine Yet the typewriter continues to persecute her When she finally discovers the author of the letters, the policeman arrives, preventing another time from striking the criminal hand which was none other than that of Mrs Wollmer, murderer of her husband