G. K. Chesterton 
Man Who Knew Too Much 

Horne Fisher is "The Man Who Knew Too Much" in these eight stories. In the final story, "The Vengeance of the Statue", Fisher notes: "The Prime Minister is my father’s friend. The Foreign Minister married my sister. The Chancellor of the Exchequer is my first cousin." Because of these intimate relationships with the leading political figures in the land, Fisher knows too much about the private politics behind the public politics of the day. This knowledge is a burden to him in the eight stories, because he is able to uncover the injustices and corruptions of the murders in each story, but in most cases the real killer gets away with the killing because to bring him openly to justice would create a greater chaos: starting a war, inciting Irish rebellions or removing public faith in the government… (Excerpt from Wikipedia)