Chinatown

It is set during a heat wave in 1930s Los Angeles, whose residents are suffering from a water shortage as a result of an ongoing drought. Private investigator Jake Gittes (Jack Nicholson) runs a detective agency specializing in matrimonial strife and infidelity. When a client posing as the wife of the L.A. water commissioner hires him to spy on her husband, who is rumored to be having an affair with a younger woman, Jake uncovers a plot against the commissioner--but this is only the tip of the iceberg.