Set in Oklahoma atop the underground oil reserve that existed under the Osage territory, this true crime book follows a series of murders that compose a disturbing conspiracy that reigned and raged across the Osage community in the 1920s. A tremendously wealthy community--due in large part to the "headright" system that granted each Osage Native American a share of the oil profits--the Osage suffered a horrific series of mysterious deaths and obvious murders, beginning in 1921 and spanning several years, creating a widespread sense of paranoia and drawing in the nascent FBI. 

I loved the first section of this book, which set the scene and introduced the characters with a wonderful sense of suspense. I was fascinated by this story that I had never heard before, and I didn't want to turn the book off to go to work! However, the subsequent sections were disappointing. The second section, at least nominally, addressed the development of the FBI, as suggested in the subtitle of the book, but I found this part incredibly hard to follow and lacking in detail. Indeed, from the text of the book, it seemed that the FBI existed long before its pursuit of this case, and I didn't entirely understand the connection. The third section of the book was essentially an unnecessarily long Author's Note, reviewing Grann's research and writing process. I love Author's Notes in general, but this was a bit too much and simply established uncertainty regarding the research.