A finger in a wasps’ nest

Student Anna, a distant relative of Viktor Palec, is spending part of her holidays at the family cottage in Kročín. While clearing out the annexe, she comes across old documents concerning the adoption of her uncle, Tomáš. He tragically died in the floods of 1997, long before Anna was born. Anna becomes interested in his fate and starts asking witnesses and Viktor about it. However, she soon begins to receive threatening messages, and a witness to Tomáš's death is found dead. Could it be that things were different back then during the floods?