Martin Scorsese's Killers of the Flower Moon mostly unfolds in the 1920s, when some of the richest people in America were members of the Osage Nation in northeast Oklahoma. Having discovered oil beneath their land years earlier, the Osage live in beautiful homes, own expensive cars and employ white servants.

As in his earlier period dramas, like The Age of Innocence and Gangs of New York, Scorsese brings a highly specific bygone era to vivid life. But this story of enviable wealth is also one of exploitation. The Osage don't control their money; the U.S. government has assigned them white guardians to oversee their finances. Many Osage women are married to white men, who are clearly eyeing their wives' fortunes.

The movie, adapted from David Grann's 2017 book, is structured around one of these marriages. Leonardo DiCaprio plays Ernest Burkhart, a handsome, slightly feckless World War I veteran. He's come to Oklahoma to live with his uncle, William K. Hale, a wealthy cattle rancher and beloved community pillar played by Robert De Niro. Soon Ernest finds work as a driver for Mollie Kyle, a quietly steely Osage woman played by Lily Gladstone, whom you may recognize from the series Reservation Dogs and movies like Certain Women.

Ernest is a flirt, and while she initially resists his advances, Mollie eventually falls for him. They marry in a visually stunning wedding sequence that shows the panoramic sweep of Rodrigo Prieto's cinematography and the exquisite detail of Jacqueline West's costumes. But even as they settle down and start a family, Mollie begins to lose hers. Her mother and sister succumb to a mysterious illness. Another sister is found shot to death in the woods. Many more Osage victims turn up, suggesting an intricate criminal conspiracy at work.

Grann's book unraveled that conspiracy gradually, through the eyes of Tom White, a dogged investigator for the FBI; he's played here, very well, by Jesse Plemons. But the movie diminishes his role considerably and reveals what's going on pretty much from the start: White men are systematically murdering the Osage for their headrights, their legal claims to this oil-rich land.

What's so unsettling is not just the ruthlessness but the patience of this scheme; whoever's plotting these chess moves, arranging marriages, devising murders and controlling who inherits headrights, is playing a very long and elaborate game. Killers of the Flower Moon is very long itself at three-and-a-half hours, but it's also continually gripping; Scorsese and his editor Thelma Schoonmaker are masters of the slow burn.

Whatever's going on, it's clear that De Niro's Hale is at the center of the mystery — not just because of the cunning twinkle in his eye, but also because he bears the darkly iconic weight of the actor's past roles in GoodFellas, Cape Fear, The Irishman and other Scorsese dramas.

DiCaprio, also a Scorsese veteran, is equally good as Hale's gullible lackey, who gets drawn into this cold-blooded plot. When Mollie falls very ill, a chill runs through the entire picture: Could Ernest really be killing the mother of his children, a woman he genuinely seems to love?

Mollie herself doesn't know what to think. Gladstone's captivating performance makes you feel her turmoil, as well as her unrelenting grief as her family members keep dying.

Scorsese wants to honor those victims, and to show how they fit into the long, brutal history of Native American displacement and death. After spending decades exploring America's mean streets, he's addressing the country's original sin. Much of the pre-release buzz has focused on the care that he took, working with Osage consultants to present an authentic depiction of Indigenous life. Even so, some have asked whether a white man should be telling this story — a question that Scorsese seems to acknowledge in one powerfully self-implicating scene.

To my eyes, the movie does have a framing problem, but it's mainly because of its jumble of perspectives. Scorsese gives just enough attention to Mollie and the other Osage characters that I wish he'd centered them even more. But the movie's true interest seems to lie elsewhere. Killers of the Flower Moon may be a fresh departure for Scorsese, but it also finds him on perhaps too-familiar terrain, transfixed as ever by the violence that men do and the trauma that they leave behind.