Knife in the Water (Polish: Nóż w wodzie) is a 1962 Polish psychological thriller film co-written and directed by Roman Polanski in his feature debut, and starring Leon Niemczyk, Jolanta Umecka, and Zygmunt Malanowicz. Its plot follows a husband and wife who are accompanied on a boating trip by a young male hitchhiker, who spurs a number of...