Set in a wintry, haunting Prague, the mysterious Piper arrives at New Year’s Eve in a red car and meets Agnes and Kristian, who are struggling with social rejection and a pending marriage. Using his magical flute, he purges the city of rats—and later, corrupted townspeople—demanding a personal sacrifice in return for love and redemption.

In the 1950s, Ludvik Jahn was expelled from the Communist Party and the University by his fellow students, because of a politically incorrect note he sent to his girlfriend. Fifteen years later, he tries to get his revenge by seducing Helena, the wife of one of his accusers.