There’s a stranger in this dusty, 1870 New Mexican town. But as it’s just after the Civil War, this stranger, packing a Remington six-shooter, is Black.

Rail thin, served, but “barely,” in the log-cabin excuse for a saloon, asked for “papers” just to board the stagecoach, even though “I’m free,” glared at and hounded, Mo Washington is inclined to cynicism in voice-over narration form.

“We were free, but we had no place to be free.“

This stagecoach ride to Colorado will test Mo’s mettle and underscore Mo’s worth. Road agents will attack, kill and wound and crash the coach. Commanche will pick over the wreckage. And Mo —“Surrounded” — ” will need that Remington, that Civil War experience, to get out of this fix alive and make it to Colorado.

This sturdy and nervy Western punches through a checklist of tropes and conventions of the genre, and throws in a cross-dressing twist. Because while the hard men and harrumping women Mo runs into might think little of Mo’s thin frame and that more Michael Jackson than Chris Tucker high voice, we recognize Letitia Wright from “Black Panther,” “Black Mirror” and “Death on the Nile.”

Mo has passed herself off as a man to fight in a war, get good with a gun and get her hands on a deed to a piece of property in Colorado “for my people.” And damned if desperados, Indians and garden variety Old West racists are going to keep her from her destination.

Jeffrey Donovan plays the one man on that coach willing to look past race and the “Is that a man or a boy?” questions others have about Mo. When the infamous Tommy Walsh (Jamie Bell) and his gang attack and the attack goes wrong — Guess where the stagecoach winds up? — the survivors tie him up, Wheeler (Donovan) will go for help and guess who is left behind to watch the prisoner?

Bell is in fine form here, an outlaw given to violent, spitting rages and sweet-talking negotiations.

“I fought for your kind in the war,” holds no truck with his guard, whose “secret” Walsh is the first to figure out.

With the threat of the rest of Walsh’s gang coming to fetch him in “Commanche country,” the possibility that nobody will return to take him off her hands and the extent of her plight becoming plain, Mo isn’t hearing it. “You the one in chains,” “white boy.” Don’t try to make that “We’re a lot alike” speech in a country where they “hang a Black man from a tree cuz he’s in the wrong place at the wrong time.”

The middle acts of “Surrounded” see less pounding through Western tropes and more grinding through two-hander “debates,” with the occasional escape attempt and encounter with the natives to break up the monotony.

Michael Kenneth Williams made his last performance memorable as a stranger who comes in the dead of night “to help,” but whom Mo and especially Walsh regard with suspicion crossing over into malice.

The action sequences are well-shot and edited, as Wright handles pistols and fight choreography almost well enough for us to discount her model-thin throw-weight’s impact on the physics of a punch.

But her performance has a simmering inner fire that balances nicely with Bell’s over-the-top panic and fury.

Donovan and Williams give the picture gravitas and instant credibility as entirely convincing Western “types” — men of violence with a hint of humanity.

Although some discount this thriller for its simplicity and middle act shortcomings, genre fans will relish its grit, grim dilemmas and period-perfect detail, all in service of an entertaining and believable yarn that honors both the history and the erased history of the American West.

Rating: R, violence, profanity

Cast: Letitia Wright, Jamie Bell, Augusta Allen-Jones, Brett Gelman
Michael Kenneth Williams and Jeffrey Donovan.

Credits: Directed by Anthony Mandler, scripted by Justin Thomas and Michael Pagana. An MGM release on Amazon Prime.

Running time: 1:41