The film is adapted from the best-selling book "Killers of the Flower Moon: The Osage Murders and the Birth of the FBI" by David Grant, focusing on the "Osage Indian Mur ders" in Oklahoma, USA in the 1920s. At that time, the Osage people received huge income due to the discovery of oil mines in their original residence. Some people planned serial murders to prevent the above arrangement. In four years, 60 people were killed, shocking the country. For this reason, the U.S. government established the "Bureau of Investigation"(the predecessor of the FBI) to conduct an inter-departmental investigation, exposing that the "Osage Guardians Project", which protects the rights and interests of the Osage people, was extremely corrupt; in the end, even under a large amount of evidence, only a few murders were prosecuted.