New York City homicide detective Frank Keller is a burned-out alcoholic. His wife left him and married one of his colleagues, and he is depressed about reaching his 20th year on the police force. He is assigned to investigate the murder of a man in Manhattan, shot dead while face down in his bed, naked, listening to an old 45rpm recording of "Sea of Love (song)." Keller has three clues — a lipstick-smeared cigarette, a want-ad that the dead man placed in a newspaper, and fingerprints of the perpetrator.