"Killers of the Flower Moon" is a non-fiction book by David Grann that explores a series of murders in the 1920s targeting the Osage Nation in Oklahoma. The Osage people had become wealthy due to oil discovered on their land, leading to a wave of violence and greed as outsiders sought to claim their wealth. The book details the investigation led by the newly formed FBI under J. Edgar Hoover, highlighting the systemic racism and corruption that allowed these crimes to occur. It sheds light on the broader implications of these events in American history and the struggle for justice faced by the Osage community.