Klesko tries to change her lifestyle and become self-reliant after her sister, Gina, got married and moved to her husband's house, so she decides to join the German police. Klesko's first mission was to go to a German city (Gorlitz) to protect the Lutzkampport family, which at that time was one of the well-known and prominent families in the city.

The family requested help from the German government due to the occurrence of strange incidents and their receipt of an anonymous letter in the house, so the government sent the French investigator John Agroa to investigate the conditions of the Lotscomport family's home, learn about the strange events that occurred in the house, and the story of the anonymous letter that the family found.

The government has also sent two policemen to protect the family, (Francis and Klesko), but the events change from strange accidents and an unknown letter to dark secrets and murders.