Apple Studios has dropped a trailer for Martin Scorsese’s hotly anticipated film adaptation of David Grann’s bestselling nonfiction book Killers of the Flower Moon: The Osage Murders and the Birth of the FBI.

Grann’s 2017 book, a finalist for the National Book Award, recounts the slayings of members of the Osage Nation in Oklahoma in the 1920s. In a starred review, a critic for Kirkus wrote of the book, “Dogged original research and superb narrative skills come together in this gripping account of pitiless evil.”

The trailer features a voiceover from Leonardo DiCaprio, who stars in the film as Ernest Burkhart, a white man married to Mollie Burkhart, an Osage woman whose family members were murdered.

In the voiceover, DiCaprio reads from a book that features a chapter on Osage culture and history. “The Osage took their name from Missouri and Osage rivers,” he says in a Texas accent. “Ni-U-Kon-Ska. Children of the Middle Waters. Move, said the great white father. There are many, so many hungry wolves. Can you find the wolves in this picture?”

The trailer features shots of DiCaprio with Mollie Burkhart, played by Lily Gladstone, as well as other cast members including Robert De Niro, Jesse Plemons, and Brendan Fraser. Also appearing in the film are John Lithgow, Tantoo Cardinal, Jason Isbell, and Sturgill Simpson. The movie was written by Scorsese and Eric Roth (Forrest Gump, The Insider).

Killers of the Flower Moon will premiere in select theaters on Oct. 6 before expanding on Oct. 20 and then streaming on Apple TV+.

Michael Schaub, a journalist and regular contributor to NPR, lives near Austin, Texas.