The Mire'97 begins during the "flood of the century" that hit southwestern Poland in the summer of 1997. The city's levees burst and the unbridled element floods part of the city and the forest on Gronty. The water uncovers human remains buried in the forest, as well as the body of a teenage boy who is believed to be an accidental flood victim. These two events, only seemingly unrelated, uncover a series of mysteries in the town. Gronty is now a crime scene which will be solved by Anna Jass (Magdalena Różczka) - an uncompromising policewoman from Warsaw - and the local inspector Adam Mika (Łukasz Simlat). Meanwhile, Piotr Zarzycki (Dawid Ogrodnik) returns to the city to become the new editor-in-chief of "Kurier". Witold Wanycz (Andrzej Seweryn), on the other hand, seems to have the answers to most of the questions asked by the police. His life, however, is consumed by memories that give him no peace.