Martin Scorsese, at 80, has made one of his most morally serious films. Killers of the Flower Moon is three and a half hours of slow-building horror — a procedural about how white America stole Osage wealth through marriage, murder, and casual cruelty in 1920s Oklahoma.

Lily Gladstone is the film. Her Mollie Burkhart watches her family die one by one while her husband Ernest (Leonardo DiCaprio) lies, dotes, and lies again. DiCaprio plays Ernest as a man too stupid to grasp what he’s doing and too weak to stop. Robert De Niro’s King Hale is one of the great American villains: a banker who calls himself a friend of the Osage while orchestrating their extermination.

Scorsese is not interested in resolution. The film’s final framing — a radio drama mocking the killings — implicates everyone who treats this history as a story.