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 relative was shot, another was poisoned. More and more Osage were dying under mysterious circumstances, and many of those who dared to investigate the killings were themselves murdered.  That is the basis of "Killers of the Flower Moon" by David Grann, this week's book on Rick's Reading List.