On a remote homestead on the Martian frontier, a family from Earth clings to hope for a better life. But when strangers appear in the surrounding hills and attempt to run them off, nine-year-old Remmy (Brooklynn Prince) catches a glimpse of the desperate reality her parents, Reza (Jonny Lee Miller) and Ilsa (Sofia Boutella), have tried so hard to keep from her. The strangers attack. Remmy’s parents kill two and Reza pursues the third into the hills. Remmy waits with her mother through the night…but Reza never returns. Instead, the surviving stranger appears, clutching the stock of Reza’s rifle. He gives them the option to leave, but Ilsa, for reasons unclear to Remmy, refuses. They thus begin an uneasy détente with the stranger, who, introducing himself as Jerry, quickly insinuates himself into the daily rhythms of the homestead. Soon enough, Remmy begins to suspect a budding relationship between Jerry and her mother. Angered by Ilsa’s apparent betrayal, she decides to turn her back on the only place she’s ever known and sets off into the hills…only to discover how little choice her mother, and she, actually have.