Robert De Niro, Leonardo DiCaprio are out for blood in exclusive “Killers of the Flower Moon ”clip

It's been 30 years since Leonardo DiCaprio and Robert De Niro first worked together, playing stepson and stepfather in 1993's This Boy's Life. Now, the two actors are reuniting, teaming up with Martin Scorsese for the chilling crime drama Killers of the Flower Moon.

Both DiCaprio and De Niro are longtime Scorsese collaborators, but Killers of the Flower Moon (out Oct. 20) marks their first time starring together in one of the director's films. Scorsese and writer Eric Roth adapted the film from David Grann's best-selling book, which chronicles the brutal Osage murders of the 1920s and the early days of the FBI. De Niro plays imposing Oklahoma businessman William Hale, the self-proclaimed "King of the Osage," while DiCaprio stars as his loyal nephew Ernest Burkhart. Ernest, a World War I veteran, strikes up a romance with Osage woman Mollie Kyle (Lily Gladstone), and before long, the two men start to weave a tangled web of secrets and murder.

In EW's exclusive clip (above) from the film, Hale and Ernest argue about a contracted killing gone wrong. "It's supposed to be a suicide, you dumbbell!" Hale yells. "You didn't tell him to leave the gun?"

"I don't know why!" a panicked Ernest replies. "I told him to leave the gun, just like you told me. I don't know why he didn't!"

Apple Original Films Robert De Niro and Leonardo DiCaprio in 'Killers of the Flower Moon'

Last week, Scorsese spoke to a group of journalists about reteaming with DiCaprio and De Niro, explaining that it was De Niro who first suggested he cast DiCaprio for 2002's Gangs of New York.

"Bob introduced me to Leo years ago," Scorsese told reporters at a recent press conference. "Turns out that when Leo and I started to work together, I discovered we had similar sensibilities that Bob and I had. He was also brave enough to go to places the way that Bob would — difficult places. [He had] a fearlessness about performing and trying anything."

Scorsese added that despite their similarities, DiCaprio and Scorsese each have a different way of working. "I found I could work with [Leo] if I talked with him a lot," Scorsese explained. "His method for me is a method of constant conversation, constant exploration. With De Niro, it's a little different. Yes, there's talking, but then there's quiet. … So, the two together played off each other so beautifully."

Apple will release Killers of the Flower Moon in theaters worldwide Oct. 20. Watch the exclusive clip above.

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