A group of Mexican migrant workers seek a better life by crossing the US border illegally; when the truck carrying them breaks down in the middle of nowhere, the driver points the migrants and his partner Mechas in the direction of the United States and wishes them luck. Moises is also a member of the migrants and follows as the group splits in two while trying to pass the border. Sam is a merciless, rifle-toting vigilante who, with his faithful but vicious Malinois dog, Tracker, hunts for rabbits near the border and notices the group trespassing; with the help of Tracker and the use of his M1 Garand rifle, Sam kills most of the group, including Mechas and leaves Moises and Adela as the sole survivors after a long chase. Unable to follow the last two, Sam decides to continue his hunt the next day and leaves with Tracker. Adela and Moises find a spot to rest, with Adela confessing to Moises that her companion, who was one Sam's victims, was sent by her parents to protect her and even though he molested her during their journey, he didn't deserve to die that way. Moises confesses to Adela that he had already been to the USA and that he has a family waiting for him in Oakland, showing a talking teddy bear which his son gave to him before being deported, and that Moises promised him he would bring it back. Meanwhile, Sam rests by a campfire with Tracker, describing to his loyal dog how he used to love the desert but now the heat is playing with his mind and he wants to escape from it. The next morning Adela and Moises steal Sam's truck, using the teddy bear to distract Sam and Tracker. The duo manage to start the truck and seem to have finally escaped when Sam shoots Adela in the shoulder, causing Moises to crash the truck. They continue on foot, followed by Sam and Tracker. Moises stops to take care of Adela's wound, then tells her he has to leave her and takes Sam's jacket and flare gun with him. Moises has a change of heart and uses a round of the flare gun to distract Sam from Adela; Tracker closely pursues Moises in a cactus field where Moises is forced to use the flare gun on Tracker and shoot him in the mouth before escaping; Sam finds a mortally wounded Tracker and reluctantly shoots him to end his suffering before swearing vengeance on Moises. After a long time chasing Moises as they are climbing on a rock structure, Sam is dehydrated and tired; Moises hides between the rocks and pushes Sam as he is standing on the edge, causing both of them to fall and breaking Sam's leg in the process. Both try to reach the rifle, but Moises takes it and menaces Sam with the rifle for murdering so many people and trying to kill Moises and Adela as Sam begs for his life, for forgiveness, and for water. Instead, Moises leaves with the rifle, telling Sam that the desert will kill him and leaves Sam to die despite his pleas for Moises to come back. Moises returns for Adela; he finds her alive, but unconscious, and carries her until they cross a salt lake.
, the film holds a 63% approval rating on Rotten Tomatoes, based on 90 reviews with an average rating of 5.71/10. The site's consensus reads "Desierto's thought-provoking themes and refreshing perspective are unfortunately offset by a predictable plot and thinly written characters." On Metacritic, the film has a score of 51 out of 100, based on 24 critics, indicating "mixed or average reviews". Dave Robinson of outlet Crash Landed reviewed the home entertainment release of Desierto awarding it 3 stars, taking note of its technical acumen in providing a thriller, but its "ill-defined script accomplishing nothing beyond passive entertainment" and of special note its complete lack of special features.
