“Waiting for the Barbarians” is a dusty, grim colonialism fable based on a novel by the South African Nobel laureate J. M. Coetzee.

The “waiting” ostensibly is the comeuppance facing an unnamed “empire” whose brutal high-handedness will lead to a third act reckoning. But the “barbarians,” our hero comes to see, are the “civilized” faces looking back at himself and his kind when they shave each morning.

It’s a sort of old fashioned movie, as 19th century period pieces set in forts in the desert inevitably are, but more intimate than grand in scope and scale.  The literary qualities and a very good cast make it work, despite “FABLE” being spelled out in capital letters as Colombian director Ciro Guerra (“Embrace of the Servant”) and the novelist-screenwriter never let us forget its Great Book origins.

Mark Rylance is The Magistrate, an imperial functionary too-long-on-the-job at a frontier outpost to wield the jackboots of authority. “One grows to feel a part of the place,” he says, shrugging off his “leave well enough alone” attitudes to his superior, Col. Joll, played with a quiet menace by Johnny Depp.

Joll is all about the jackboots, traveling in the comfort of a coach with similarly black-clad imperial troopers. His only concession to the desert is his exotic eyewear, “the latest thing,” sunglasses.

The setting could the Himalayan foothills where the British, Russian and Ottoman Empires collided, or the Atlas Mountains of Morocco, where the French Empire held sway, and the actual filming location. But the idea is that racism and the “colonial” impulse are timeless, the ugliest part of human nature, no matter if you’re German, Japanese, American or Belgian.

Joll is curious about “threats” from across the border and why The Magistrate has done nothing about them. The Magistrate has been there long enough to dismiss that “hysteria” as nothing more than gossip. He sees the nomadic neighbors as a minor nuisance at worst, eternal in that they’re just waiting for this latest “empire” to leave them be.

“I kept the world on its course,” he says of his duties there, explaining why he never built a jail as he shows the Colonel two sheep-stealing nomads they’re holding for trial in the fort.

But Joll is here to crack the whip, bring the boot down and “interrogate” the prisoners. The Magistrate’s protests of “What could they possibly know?” fall on deaf ears. There is a “set procedure,” applying “patience and pressure to get to the truth.”

Thus is the order of this quiet, peaceful backwater shattered, the violence escalating towards war — to confine the “barbarians” to the distant mountains.

It plays out in an understated, if author-underlined fashion. “What is war,” one junior officer (Sam Reid) notes, but “compelling a choice on someone who would not otherwise make it?”

There are screen “chapter” headings such as “Spring: The Return.” And there is The Girl (Gana Bayarsaikhan), a torture victim whom The Magistrate nurses and tries to return to her people.

All for naught, as reinforcements and Robert Pattinson, as Officer Mendel, arrive and an ill-conceived “campaign” is mounted, barbarism piling upon barbarism.

You have to have a high tolerance for characters as archetypes, for an author channeling Franz Kafka in his dismay at the misdirected, misguided and misanthropic machinery of state, to embrace a movie such at this.

The “Lawrence of Arabia/Beau Geste” setting notwithstanding, Guerra never reaches for Cinemascope grandeur. A desert trek, complete with sandstorm, is his only concession to that.  These are ordinary men committing atrocities in a drab place no one should be fighting to rule.

The Oscar-winning Rylance is perfectly-cast as the “one just man” Joll insults him for wanting to be. He’s quite good at conveying innate decency.

Depp could be dismissed as just a name and a costume who got the film financed, but his Franco-Teutonic take on Joll never quite crosses into caricature. It’s good to see him putting in the effort. Pattinson? His tiny part basically is just a name and a costume who got the film financed, although he acquits himself well enough.

Greta Scacchi plays a woman of the garrison, a role that must have had more to it in the novel.

“Waiting for the Barbarians” may keep Coetzee’s fable elements intact, but one wonders if something richer might have come from it with another screenwriter adapting the book, or perhaps a director with a bigger reputation behind the camera.

Yes, we get “the moral of the story.” It’s embossed and burnished, if not quite beaten into us. But you can’t help feeling there should have been more here to make “Barbarians” worth the wait.

MPAA Rating: unrated, bloody violence, torture

Cast: Mark Rylance, Johnny Depp, Gana Bayarsaikhan, Robert Pattinson, Greta Scacchi and Sam Reid.

Credits: Directed by Ciro Guerra, script by J.M, Coetzee, based on his novel.  A Samuel Goldwyn release.

Running time: 1:52