Knife in the Water (Noz W Wodzie) was the first feature film effort of Polish director Roman Polanski. Sportswriter Leon Niemczyk and his wife Jolanta Umecka invite baby-faced hitchhiker Zygmunt Malanowicz to join them on a yacht excursion. Sensing that his wife is attracted to Malanowicz, Niemczyk plots to humiliate the boy by showing off his own athletic prowess during the cruise.