“With Joaquin, things went quickly because I wanted to work with him and so did John,” Audiard said in an email (the interview was conducted through a translator). “During and even after filming [Reilly and Phoenix’s] has been a kind of schoolboy camaraderie. At the start of The Sisters Brothers, each of the brothers has for a long time played his part as a sibling. Charlie is the younger, handsome and impulsive, a little mad and therefore charismatic; Eli is the big brother who is rough, blinkered, and not a natural charmer. As the story progresses, their roles, if not exactly reverse, at least change; Eli gains in heroic and charismatic stature.”

In the book, Eli’s somewhat sad-sack nature is reflected by his pathetic horse Tub, an unimpressive, lumbering animal that earns his master’s sympathy, despite being the polar opposite of Charlie’s horse Nimble. Reilly’s performance is similarly lovable, with more than a hint of brutishness. Meanwhile, Phoenix does his most devilishly winsome and fun work in years, quite distant from his more muted (but stellar) turns in You Were Never Really Here or Her.

With its painterly visuals (shot by Benoît Debie), dramatic landscapes, and nasty gunfights, the film recalls many classic Westerns, even as its narrative is much more amoral and haphazard, with the brothers bouncing from town to town, leaving behind a bloody swathe. “Our model was more telling a tale outside the Western tradition,” Audiard said. “One can see in The Sisters Brothers how these are two children in the bodies of weary adults … The violence is treated like imagery in a storybook: It’s exaggerated and visual, and meant to be taken at a remove from reality.”

The film’s weariness with much of the Western genre’s traditional iconography is obvious, particularly the notion that the man with the fastest gun is the hero. The Sisters brothers are paid assassins, contracted by the mysterious Commodore (Rutger Hauer) to wreak havoc across Oregon and California, but there’s nothing remotely valiant about what they do. The novel, and the film, succeeds because of that honesty, and because of Audiard’s effort to find humor and humanity in characters who outwardly display very little of those qualities (aside from Eli’s love for Tub).

“I think that it’s the forthright and uncompromising virility of the heroes of classic Westerns that has kept me at a distance from the genre,” Audiard said. “My taste runs to those that came later, ones that I saw coming of age in the 1970s: The Missouri Breaks, Little Big Man, Jeremiah Johnson, etcetera. The movie that was most on our mind during the screenwriting process isn’t a Western but rather a dark fairy tale: The Night of the Hunter.”

Audiard has long made films about flawed men struggling against their darker instincts, a world away from the white-hatted champions of Hollywood’s Golden Age. “For me, between childhood and adolescence, the movies were a powerful educator,” he said. “They informed me about life and the world, women and men. As a teenager, cinema without a doubt helped me learn about girls; Paul Newman, Marcello Mastroianni, Jean-Louis Trintignant, Jean-Paul Belmondo, and others have my gratitude. But as far back as I can remember, there was no learning about how to talk to girls from watching John Wayne.”