In The Sound and the Unsound, private investigator Philip Marlowe finds himself drawn into a peculiar case when he encounters Lucille Bellows, an elderly woman who has taken to napping outside his apartment door. Lucille, who claims to have been hearing strange noises from her neighbor's bungalow, seeks Marlowe's help to uncover the truth behind these unsettling sounds. Despite his initial reluctance, Marlowe is intrigued by her story and agrees to accompany her to investigate.