Murder and machismo, that’s what you’re in for when you sit down to watch The Sisters Brothers. Charlie and Eli Sisters are a couple of guns for hire. They care deeply about maintaining their bad reputations, which shouldn’t be a problem as long as they keep working for The Commodore, a fearsome and violent man.

Their next mission, should they choose to accept it: kill Herman Kermit Warm (Riz Ahmed), who’s got something The Commodore wants. A professional scout, John Morris (Jake Gyllenhaal), is already tracking him, and once located, the Sisters Brothers ride in for the dirty work.

Joaquin Phoenix and John C. Reilly play the brothers – Phoenix the younger brother, Charlie, but natural leader of the two. He’s more violent and more gung-ho. Reilly, on the other hand, gives Eli a slightly sweeter disposition. He dreams of retirement but remains in the game to keep watch over his brother, who’s a drunk always looking for trouble, and always, always finding it. Eli pines for a woman who was kind to him once. He laments the fate of his pitiable horse. He cuts his brother’s hair.

When the foursome finally meet up, Herman isn’t the villain everyone anticipated, and his commodity proves irresistible to anyone who hears about it. But if his body and potion aren’t offered up to The Commodore in a hurry, there’ll be hell to pay. With allegiances divided and a different ending standing tantalizingly before them, what will the Sisters Brothers choose, and how will the body count be affected? Because there WILL be a body count, make no mistake on that.

The Sisters Brothers is adapted from a book I absolutely adored and passed around to nearly everyone I know, by  Canadian author Patrick DeWitt. John C. Reilly also read it and loved it, and he optioned the book in 2011; he produces this film alongside his wife, Alison Dickey, an indie film producer he met on the set of Casualties of War when she was an assistant to Sean Penn – they’ve been married for over 25 years). They’ve tapped French director Jacques Audiard to helm this shoot-em-up western, and Audiard gives it a sensibility that’s weird and eccentric. Not your typical western, not your typical anything. It’s as funny as it is violent, and both characters and story break out of the genre frequently enough to surprise you.

The acting is great. Riz Ahmed especially gives Herman’s character a bit of a twist, colouring the movie with a slightly more optimistic or meditative vibe. But of course the film belongs to Reilly and he knows it. Though I wish we would have spent a little more time with Eli alone, away from his brother’s influence, deeper into his psyche (flashbacks, I suppose, would have been nice), there’s still something very special going on there, something half-sweet (Eli is still a bad man), half-innocent, half-introspective, half-other-worldly. These aren’t necessarily the kind of cowboys you’re used to but I enjoy the genre’s subversion, the clever hacks that elevate it to something unique and fun to watch. DeWitt’s novel is quite good and I urge you to read it. But unlike many adaptations, this film captures some of its surprising warmth. Despite the Sisters Brothers being contract killers, we find a fair bit of compassion for them as they unravel the traumas of their past and seek a path forward, perhaps not quite forged in enlightenment, but in understanding, and from a need to do and be better.

Charlie and Eli are a some of the most interesting characters to come out of the western genre. Charlie simmers with anger. Eli ooze regret. The brothers bicker like an old married couple but they have each other’s backs when needed – and if often is. But no matter how much sympathy we’re feeling for them, Audiard doesn’t shy away from the fact that the guns on their hips are used to commit murder, for money. Their morals are for sale to the highest bidder. It makes them complex, and eminently watchable.