[Source: AP]

Late in Martin McDonagh’s new film “Wild Horse Nine,” John Malkovich’s CIA agent Chris describes an idea for a Western told from the point of view of the horse.

It would be a “downbeat Western,” he tells his partner Lee (Sam Rockwell), who laughs: “There’s no way I’m seeing that Western.”

It’s McDonagh’s self-conscious nod to the fact that he is wrapping up his own downbeat Western, a darkly comedic and mournful tale of regret and atonement at the end of a life of violence.

After a career devoted to killing and regime-toppling for the U.S. government, Chris is staring down his own death for a decidedly less cinematic reason — cancer — and his thoughts are scattering.

For Lee, as he listens to Chris’ nonstop chatter, it has become difficult to distinguish between the nonsense and the truths.

The two men are on a trip to Easter Island. It’s 1973, they’re stationed in Santiago, Chile, and they know the dark future awaiting their adopted home:

On Sept. 11, Gen. Augusto Pinochet will lead a violent military coup, seizing power from and killing the democratically elected president, Salvador Allende. This is business as usual for Lee and Chris, but Chris has been getting a little loose-lipped lately.

“Enjoy him while you can,” Chris tells two young Allende fans, Monica (Mariana di Girolamo) and Alicia (Ailín Salas), at the airport.

He also says they are indeed in the CIA and in Chile to destabilize the government, which Lee attempts to play off as a joke. But, for now, they’re off to see “the big heads.”

There is something sinister looming over this vacation, however, and it’s not just the upcoming coup. One way or another, Chris is not likely to make it off Easter Island alive.

Their boss, MJ (a cranky and amusing Steve Buscemi), knows about Chris’ plans to write a memoir and has tasked Lee with finding out what’s in it.

They are particularly concerned about any information regarding a certain presidential assassination in Dallas in 1963.

And soon after they get off the plane, MJ is already aware of the airport gaffe; someone is watching Lee watch Chris and reporting back.

This is familiar territory for McDonagh, who continues to be drawn into the realm of male friendships and heightened scenarios in picturesque locations, from “In Bruges” through “The Banshees of Inisherin.”

Lee and Chris’ conversations mostly consist of bickering, but the layers of this oddball coupling begin to shed and reveal something substantial and deep.