With its lovingly created 1930s setting and its pleasingly intricate plot, Chinatown might initially induce nostalgia: by the end, one is all but overwhelmed by the scale of sexual and political corruption uncovered by a detective who assumed he was investigating a minor case of marital infidelity. Jack Nicholson as the private eye and Faye Dunaway as the woman of mystery inhabit the Bogart-Bacall roles of old, but times have changed. The hero is not as smart as he thinks he is; the heroine’s brittle wit is a cover for neurosis; and the revelation of the woman’s private anguish turns the hero’s habitual cynicism into genuine horror. Writer Robert Towne and director Roman Polanski assault the complacencies of the traditional detective yarn, where a knight-errant hero ensured justice was done. Polanski shows the limits of individualism; the invincible conspiracies of power; the irresistible allure of depravity. He imbues the mystery thriller with the weight of tragedy.