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

Then, one by one, the Osage began to die under mysterious circumstances. In this last remnant of the Wild West, many who dared investigate the killings were themselves murdered.

As the death toll climbed, the FBI took up the case. It was one of the organization's first major homicide investigations and the bureau badly bungled it.

In desperation, the young director, J. Edgar Hoover, turned to a former Texas Ranger named Tom White to unravel the mystery. White put together an undercover team, and agents infiltrated the region. Together with the Osage, they began to expose one of the most chilling conspiracies in American history.

This is the story told in David Grann's nonfiction whodunit, "Killers of the Flower Moon." Consider reading the 2017 title, which was named a best book of the year by the Wall Street Journal, Time magazine and Library Journal, and then join the Thursday Mornings book-discussion group April 26, when the selected title is "Killers of the Flower Moon." The Thursday Mornings group meets at 10:30 a.m. on the last Thursday of the month at Old Worthington Library, 820 High St.

On March 22, Ruth Wariner's "The Sound of Gravel" will be considered. Lynda Cohen Loigman's "The Two-Family House" is up for discussion May 24.

Meanwhile, the Speaking Volumes book-discussion group's meetings are at 7:30 p.m. the first Wednesday of each month at Old Worthington Library.

This spring, participants will gather on March 7, April 4 and May 2 to talk about "The Love Song of Miss Queenie Hennessy" by Rachel Joyce, "Saints for All Occasions" by J. Courtney Sullivan and "The Essex Serpent" by Sarah Perry, respectively.

Finally, the Northwest Passages book-discussion group meets at 10:30 a.m. on the third Wednesday of each month at Northwest Library, 2280 Hard Road.

Spring book selections include "The Secret Diary of Hendrik Groen, 83 1/4 Years Old" by Hendrik Groen on March 21, "Red Notice: A True Story of High Finance, Murder and One Man's Fight for Justice" by Bill Browder on April 18 and "One Day in the Life of Ivan Denisovich" by Aleksandr Solzhenitsyn on May 16.

Hillary Kline is a communications specialist for Worthington Libraries.