A family of three works to survive on the hardscrabble frontier in writer-director Wyatt Rockefeller's debut feature Settlers. However, Settlers isn't set in the 19th-century American West. Even if Settlers has all the key ingredients of an American Western, the film mostly takes place during some unspecified amount of time in the future on the surface of Mars.

Space Westerns are nothing new, from Joss Whedon's Firefly to 2018's underrated feature film Prospect, starring Pedro Pascal. Space is, after all, the final frontier, and settling there requires the same mix of adventurousness and desperation that characterized the pioneers who traveled west in the 1800s. Those pioneers weren't the first people to actually inhabit that land, of course, and the characters in space Westerns often encounter their own versions of indigenous people and the conflicts that come with settling on someone else's land.

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Jonny Lee Miller and Sofia Boutella in Settlers

It's not entirely clear if there are indigenous sentient life forms on Mars. At first, Reza (Jonny Lee Miller), Ilsa (Sofia Boutella), and their 9-year-old daughter Remmy (Brooklynn Prince) appear to be alone in a desolate valley. Reza points out the planet Earth in the night sky, and Remmy asks her parents if they ever saw exotic Earth creatures like elephants. But their placid, isolated existence is shattered by hooded invaders, who write "Leave" on the window of the family's modular outpost and surround the compound. After an offscreen shootout, the invaders are down to just one, Jerry (Ismael Cruz Córdova), who claims that the home the family inhabits once belonged to his own family, and he's taking it back.

Settlers is divided into three sections, each named after one of the important people in Remmy's life. In the second section, named for Ilsa, Jerry settles into a sort of uneasy truce with Remmy and Ilsa, as the three of them work to make the settlement self-sustaining. They even refurbish a helpful robot that Remmy names Steve, drawing a smiley face on it and turning it into a combination of the family dog and best friend -- replacing the connections that she's deprived of by living in such a barren wasteland.

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Rockefeller never quite explains what's going on either on Earth or Mars, with characters making only vague references to wars and the destruction of cities. Settlers is intriguingly atmospheric at first, although the lack of concrete detail eventually becomes frustrating, especially once the characters start behaving erratically. The interpersonal dynamics can't make up for the narrative deficiencies if those character relationships stop making sense.

For most of the movie, though, Rockefeller creates an evocative and immersive world with minimal dialogue and sparse set design. Shot in South Africa, Settlers has a suitably harsh, worn-out look, both in the landscape and in the sets and costumes, which are believably threadbare. At best, the cryptic dialogue hints at a complex wider world, of which Settlers is just a small glimpse. Remmy is clearly fascinated by that world, and even before violence disrupts her family life, she's eager to explore beyond their homestead. Her sense of wonder and thirst for adventure are hallmarks of the best space-exploration movies.

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Ismael Cruz Cordova in Settlers

Prince, who broke through as the star of The Florida Project and plays a very inquisitive young girl on Apple TV+'s Home Before Dark, is excellent in the role, giving Remmy a balance of beyond-her-years toughness and youthful vulnerability. Remmy's clearly had to grow up quickly on this frontier, and she faces danger with confidence and bravery, even if that masks some deep-seated pain. Prince overshadows all of the adult actors around her, and while the chapters may be named after other characters, Settlers is really Remmy's story.

That's why it's such a disappointment when the third act jumps ahead 10 years or so, replacing Prince with Servant's Nell Tiger Free as Remmy. After an hour or so of limited world-building, Rockefeller struggles to figure out a way to tie his ideas together. Free's Remmy feels almost like a new protagonist showing up just as the movie should be hitting its climax.

Still, Settlers delivers an intriguing sci-fi world with slow-burning suspense and poignant musings on humanity. It's more of a promising debut than a fully realized vision, but at least Rockefeller gets tripped up by being too ambitious, rather than not ambitious enough. He has the right elements to put together a more cohesive take on sci-fi next time.

Settlers arrives in select theaters on July 23 and on VOD.

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