In the early hours of August 18, 1973, a heinous act occurs when a grave robber steals multiple corpses from a cemetery near Newt, Muerto County, Texas. The robber creates a grotesque monument by tying a rotting body and various body parts together, leaving it for local residents to discover with the morning light.
Meanwhile, a group of five teenagers embarks on a summer road trip in a van: Sally Hardesty, Jerry, Pam, Kirk, and Sally's paraplegic brother Franklin. They make a stop at the cemetery to pay their respects to Sally and Franklin's grandfather, discovering that the grave is undisturbed. Driving past a slaughterhouse, Franklin recounts the Hardesty family's long-standing connection to animal slaughter, a history that adds an eerie layer to their adventure. During their journey, they pick up a hitchhiker who recounts his own family's connection to the old slaughterhouse. The interaction takes a dark turn when he borrows Franklin's pocket knife to cut himself and takes a Polaroid picture of the group, demanding money in exchange for it. When they refuse, he burns the photo in anger and violently attacks Franklin with a straight razor. The terrified group manages to force him out of the van, leaving behind a smear of blood on their vehicle as they speed off into the distance. Running low on gasoline, they stop at a gas station but find it completely dry. Intrigued, the group explores a nearby abandoned Hardesty family home.
Kirk and Pam decide to venture off in search of a swimming hole mentioned by Franklin. However, they encounter another house with dilapidated cars and gas-powered generators. Kirk, seeking gas, heads inside through an unlocked door while Pam waits outside. Amid his search, a large man with a skin mask unexpectedly appears and brutally kills Kirk with a hammer. Pam enters the house seeking Kirk, only to stumble into a horrific scene of decaying remains and furniture fashioned from bones. In a desperate attempt to escape, Pam is caught and gruesomely impaled on a meat hook while witnessing the murder of Kirk as the butcher revs up a chainsaw.
Later that evening, Jerry goes looking for Pam and Kirk, unintentionally walking into the same house and discovering Pam's nearly lifeless body in a chest freezer. Tragically, he meets the same fate as the others at the hands of the masked murderer. As darkness envelops the land, Sally and Franklin take it upon themselves to search for their missing friends. The sinister killer ambushes them, brutally murdering Franklin with a chainsaw. Sally narrowly escapes into the house, stumbling upon an ancient, almost lifeless man and a decomposing woman's body. In a hair-raising moment, she leaps through a second-floor window and races toward the gas station. Just as she seems to gain a moment of safety, the masked man once again appears, driving her into a frantic state. At the gas station, Sally receives false comfort from the proprietor, who ultimately overpowers her and loads her into his truck.
The men transport Sally to the other house, where the hitchhiker appears, receiving a scolding from the proprietor for his earlier actions. It’s revealed that he is the grave robber. In a shocking twist, the masked man, identified as "Leatherface," is revealed to be his brother. Together, they bring down their frail grandfather, "Grandpa," and cruelly cut Sally's finger, allowing Grandpa to suck her blood, causing her to faint from terror.
As morning breaks, Sally awakens to the taunts of her captors who are eager to kill her using a hammer. Grandpa, however, is too weak to participate in their sick game. Seizing a moment of opportunity, Sally breaks free, sprinting onto the road as the brothers pursue her. In a twist of fate, an oncoming truck accidentally runs over the hitchhiker, ending his life. The truck driver confronts Leatherface with a wrench, provoking a struggle where Leatherface injures himself with his own chainsaw. Covered in blood and filled with a desperate will to survive, Sally flags down a passing pickup truck, managing to climb into the bed just as Leatherface swings his chainsaw in frustration. As the truck drives away, Sally's laughter mingles with horror, marking her narrow escape as the sun rises over the chilling events of that day.
