In the 1920s, the richest people per capita in the world were members of the Osage Nation in Oklahoma. After oil was discovered beneath their land, the Osage rode in chauffeured automobiles, built mansions, and sent their children to study in Europe.

Then, one by one, the Osage began to be killed off. The family of an Osage woman, Mollie Burkhart, became a prime target. One of her relatives was shot. Another was poisoned. And it was just the beginning, as more and more Osage were dying under mysterious circumstances, and many of those who dared to investigate the killings were themselves murdered.

As the death toll rose, the newly created FBI took up the case, and the young director, J. Edgar Hoover, turned to a former Texas Ranger named Tom White to try to unravel the mystery. White put together an undercover team, including a Native American agent who infiltrated the region, and together with the Osage began to expose one of the most chilling conspiracies in American history.

I was a fan of David Grann years before we ever met—seeing his byline was a red alert that I was about to read something special. He is a master of real-life mystery, thrilling adventure, and jaw-dropping twists (See his previous book, The Lost City of Z, now a movie, for examples of all). But above all, he is interested, passionately, in what makes people unique, and why they behave in the strangest of ways.

Few tales are stranger than the one contained in Killers of the Flower Moon, a book I consider to be Grann's masterpiece. It resuscitates the true story of the Osage Indians, an Oklahoma-based tribe who were the richest people in the United States in the 1920s, per capita, because of oil buried beneath their land. Oil that was like liquid gold. Oil that so many others salivated to possess and to exploit at all costs. Which is why, one by one, the Osage began to be murdered. Grann’s in-depth reporting and desire for the truth, combined with his palpable empathy for the victims, makes Killers of the Flower Moon true crime at its finest.

We first hear the perspective of Mollie Burkhart, a wealthy Osage woman who watches as her entire family gets picked off and who worries she'll be next. We then get the story of a former Texas Ranger named Tom White, an early member of the FBI, dispatched by J. Edgar Hoover himself to unravel the mounting mystery. And then, once the horror has abated, Grann turns the tables, widening the scope to show just how deep the rot ran, and how the violence against this Indigenous people was more systemic and calculated than first believed. It was a conspiracy of epic proportions.

Killers of the Flower Moon is an amazing, infuriating story of an American injustice. And it is all the more remarkable because of how Grann unspools the story. He never—I checked—uses the word "greed." He doesn't telegraph the outrage. He doesn't have to. History pulsates with this evil, and Grann's job, expertly done, is to show us how the repeated crimes against a marginalized group of people remain relevant today.