In David Grann’s original novel, the roles that both Robert De Niro’s William Hale and his nephew, Ernest (Leonardo DiCaprio), play in the murders at the center of its story aren’t immediately clear. However, while the team behind “Killers of the Flower Moon” tried to remain faithful to Grann’s novel, DiCaprio says that neither he nor Martin Scorsese found those versions of the film satisfying. “I think Marty and I just looked at each other and we felt there was no soul to it,” the actor told the New York Times.

In an interview with Deadline, Scorsese added, “The minute the FBI comes in, and you see a character that would be played by Robert De Niro, Bill Hale, you know he’s a bad guy. There’s no mystery. So, what is it? A police procedural? Who cares!”

The duo found what they were looking for when they landed on a version of the story that makes the involvement of DiCaprio’s Ernest apparent early on. The creative decision adds a real-time layer of complexity to Ernest’s marriage to Mollie (Lily Gladstone), an Osage woman, in the film. “The biggest challenge became pulling off the trick of not making this a mystery, but exposing Ernest early on for who he is and then watching this very twisted relationship unravel,” DiCaprio said. “That wasn’t easy and it took years to figure out.”

Thankfully, if the first reviews for “Killers of the Flower Moon” coming out of its world premiere last week are any indication, it seems like DiCaprio and Scorsese did, indeed, make the right decision when they chose to take the movie down a different path than its source material.