Description
The suburban Carter family is traveling on vacation towing a travel trailer from Ohio to Los Angeles. Parents Bob and Ethel are driving, accompanied by their teenage children Bobby, Brenda, eldest daughter Lynne, Lynne's husband Doug, Lynne and Doug's baby daughter Katy, and the family's dogs, Beauty and the Beast.
In Nevada, they stop at Fred's Oasis for fuel, and Fred urges them to stay on the main road as they leave. Fred's truck suddenly explodes. Dismissing Fred's warnings as a crazy person's ramblings, the Carters skid off a desert road and crash. The dogs become very panicky and start barking at the hills. Beauty then runs off into the hills. Chasing after her, Bobby finds her mutilated body. Frightened, he runs, falls, and knocks himself unconscious.
Bob walks back to Fred's Oasis to get help. As night falls, he finds Fred, who tells him about his son Jupiter. As a child, Jupiter killed the family's livestock and later murdered his sister. Fred attacked Jupiter with a tire iron and left him in the hills to die. However, Jupiter survived and had children with a depraved, alcoholic prostitute known as Mama. Together, they had three sons – Mars, Pluto and Mercury – and an abused daughter, Ruby. The family led by "Papa Jupiter" survives by cannibalizing travelers and stealing supplies. Papa Jupiter suddenly crashes through a window, kills Fred with a tire iron, takes Bob prisoner, and crucifies him.
Brenda finds Bobby, still shaken up about Beauty, and the two return to the trailer. Bobby does not mention Beauty's death to avoid frightening the rest of the family. Pluto sneaks to the trailer and signals Papa Jupiter to set Bob on fire as a distraction. Brenda stays in the trailer with Katy while Ethel, Lynne, Doug, and Bobby rush out to save Bob. The Carters eventually extinguish the fire, but Bob dies shortly afterwards.
As the Carters extinguish the fire, Pluto and Mars ransack the camper and Mars rapes Brenda. When Ethel and Lynne return, Mars shoots them both. Pluto abducts Katy and the brothers flee, intending for the family to eat her. Hearing their screams, Doug and Bobby rush back only to find Lynne dead, Ethel mortally wounded and Brenda traumatized.
Mars and Pluto return to their home, a cave. The Beast pushes Mercury off a hilltop to his death. Mama chains Ruby outside the cave, torments her and forces her to eat Beauty as punishment for sympathizing with the Carters. The next morning, shortly after Ethel dies, Doug sets out to find Katy while Papa Jupiter and Pluto set out to kill the remaining family members.
The Beast tears Pluto's throat out. Brenda and Bobby use Ethel's corpse as a trap to kill Papa Jupiter. Doug gets to the cave, where he sees Ruby knocking out Mama and carrying Katy away. Doug catches up with Ruby, but Mars follows and attacks Doug. Mars gains the upper hand, but Ruby interferes, enabling Doug to overpower him. Doug then savagely stabs Mars and continues long after he is dead, whilst Ruby weeps and the screen fades to red.
