Emily Blunt in Sicario (Lionsgate)

There’s a sequence in the narco thriller Sicario where we’re just watching characters driving. More specifically, it’s protagonist Kate (Emily Blunt) in a big black SUV in the midst of other big black SUVs and Mexican police patrol cars barreling through Juarez, Mexico. They’re transporting a criminal kingpin who’s part of a Mexican drug cartel. This makes everyone, even the authorities, a target, and Kate knows it. So do we, and this gives this sequence purpose and full-blown suspense. The threat of attack can happen at any moment, and the build-up is at its most succinct and palpable when the vehicles, at a standstill at the border crossing, don’t move at all.

Sicario takes a female SWAT team specialist/F.B.I. agent from Arizona and plants her in the middle of the Mexican cartels war. Kate Macer’s good, really good, so much so that she gets pegged by an American official Matt Graver (Josh Brolin), ostensibly working for the American government, and his team to come along for her expertise to find the cartel leader who ordered the slaughter that resulted in the killing of two members of Kate’s SWAT team. The term Sicario, as we’re told at the start, has a couple of different meanings: the most prevalent is that in Mexico it means hit man.

This is another film loaded to the brim with suspense from director Denis Villeneuve, like Prisoners, a tense drama that gave a lot of thrills while presenting characters in a gray, ambiguous zone of behavior. Kate is a by-the-book law enforcement official. What is she to do in an operation like this, where torturing a suspect is the standard procedure (though behind closed doors, with few around)? Or, what to make of the financial records of an arch criminal she and the team are pursuing, a target who needs to be drawn out of his hideaway like a moth to a flame?

What the new film also has in common with Prisoners are the enormously convincing performances. Blunt’s rarely been better. She has to hold a lot back and reveal only so much, and as Kate’s been trained to be professional and on-target, Blunt’s performance more often than not consists of observing, listening, taking things in, and it’s here that I found her most compelling (that and a few scenes late in the film). Brolin is Brolin and is as good as he can get, too, though his character is a little more showy; the guy with a big mouth who likes to prod people a bit more than he should. But the actor who practically runs away with the film is Benicio Del Toro, as part of the American/Mexican operation. I sometimes forget how great a force he can be, and his character gives him an opportunity to reveal a lot by, at times, doing seemingly little.

This is a violent, very brutal film, and how it’s shot is a key part of the film’s effectiveness. (A scene that involves torture is suggested, and just hearing the sounds while the camera focuses on a drain in the floor is enough.) Most of the movie is shot in the day, but it becomes become nocturnal in the second half, and it’s here that Roger Deakins shines as the cinematographer. In fact, I’d almost be inclined to credit Deakins as a (if not the) auteur of the film; how he stages and shoots action demonstrates again that he has a style distinct from anyone else: stark, direct, sometimes seemingly straightforward, while capturing landscapes with a poetic flair that is almost subtle if not painterly.

I’m reminded of the way Deakins filmed faces in No Country for Old Men or True Grit, the Coen westerns, as this is a very dark, bloody action/Western with modern warfare thrown in—a nighttime raid could almost have been out of American Sniper with its infrared technology. How an actor is lit or how characters stand in proportion to one another can be crucial to a film’s success, and in Sicario, it’s deadly serious. Without Deakins, I don’t know if it would be one of the best of the year.