The Big Sleep (1978)

Philip Marlowe (Robert Mitchum) is asked by the elderly General Sternwood (James Stewart) to investigate an attempt at blackmail on one of his daughters. He soon finds that the attempt is half-hearted at best, and seems to be more connected with the disappearance of the other daughter's husband, Rusty Regan (David Savile). Rusty's wife seems unconcerned with his disappearance, further complicating the mystery. Only General Sternwood seems concerned as mobsters and hired killers continue to appear in the path of the investigation.