William Maxwell's So Long, See You Tomorrow opens with a short chapter describing a gravel pit the narrator says he had never been to where three unnamed men heard a pistol shot that turned out to be the murder of Lloyd Wilson, a man whom the narrator never knew. It is vivid but everything is indirect, to say the least. Paul Murray's novel The Bee Sting begins "In the next town over, a man had killed his family." In both stories, the story that begins the book is not the central story but closely adjacent to it and illuminates, indeed defines, the story we are about to be told.
For this prompt, tell a story that your character or narrator is compelled by that is not their own — perhaps a rumor, a news item, or a piece of hearsay — but which is somehow meaningfully adjacent to the main story you’re telling.