On May 22, 1994, four teenagers—Barry [Tyler Shea Cone], Heather [Lisa Marie Newmyer], Jenny [Renée Zellweger], and Sean [John Harrison]—head to their school's prom in rural Texas, a night that will pull them into a nightmare far beyond typical high school drama. Heather discovers Barry cheating with another girl, and anger flares as they drive away in his car. Their argument is interrupted when Jenny and Sean, who were hiding in the backseat and smoking a little weed, join the fray. Heather takes a detour off the freeway, and in the confusion she collides with another motorist who collapses, leaving the group stranded in the dark.
Searching for help, Jenny, Heather, and Barry abandon Sean to watch over the unconscious driver, and they stop at a desolate office trailer. There they meet Darla [Tonie Perensky], an insurance agent who promises to call her boyfriend, a tow truck driver named Vilmer [Matthew McConaughey], to come and assist them. The trio leaves, planning to return to the wreck, but Heather and Barry soon find themselves separated from Jenny in the blackness. Vilmer arrives at the scene and begins a brutal spree, killing the motorist and then pursuing Sean in a truck, ramming and backing over him in a merciless display of violence.
Away from the road, Heather and Barry discover an old farmhouse hidden in the trees. Barry explores the property while Heather is attacked by Leatherface, who drags her onto the porch and finally traps her in a meat locker inside the house. W. E. [Joe Stevens], a family member, confronts Barry and forces him inside, but Barry uses his wits, tricks W. E., and locks him out. Inside, Barry finds a corpse in a bathtub and is then killed by Leatherface with a sledgehammer. With Barry dead, Leatherface drags Heather’s body onto a meat hook, sealing her grisly fate.
Jenny returns to the wreck to look for help and encounters Vilmer again, who offers her a ride but soon reveals the bodies of Sean and the other motorist hanging in the truck bed. Jenny, terrified, jumps from the vehicle and flees into the woods, but Leatherface pursues her through the farmhouse. She stumbles into rooms filled with preserved corpses, climbs out an upstairs window, and escapes into the night. Desperate, she seeks refuge with Darla, only to discover that W. E. has beaten Darla with an electric cattle prod when he arrives. They forcibly trap Jenny in Darla’s trunk and she is taken away to fulfill the killers’ gruesome dinner plans.
Her torment resumes as Vilmer hounds her, and she makes a brief escape, attempting to drive Darla’s car away. Vilmer blocks her and knocks her unconscious, only to awaken at the dinner table surrounded by the family. They reveal themselves to be part of a secret society that uses fear and ritual to terrorize people who cross their path. A refined man named Rothman [James Gale] arrives, reproving Vilmer for his brutal methods and exposing the twisted scarifications and piercings on his torso as he leers at Jenny. He leaves, and in a fit of rage, Vilmer slashes himself with a razor, then murders Heather by crushing her skull beneath his cybernetic leg, after which he knocks W. E. unconscious with a hammer.
With Jenny remaining a captive, Vilmer and Leatherface prepare to kill her, but she manages to break free. Using a remote control to manipulate Vilmer’s leg, she creates a distraction and escapes. Jenny staggers onto a dirt road and is rescued by an elderly couple in an RV, only to have Leatherface and Vilmer crash into them, sending the vehicle tumbling. Jenny crawls free and keeps running, with Leatherface and Vilmer in hot pursuit. A cropduster appears and strafes the area, striking Vilmer and killing him with a glancing wheel blow to the skull. Leatherface screams in fury as the dust settles.
A limousine suddenly pulls up, and Jenny climbs into the backseat. Rothman sits nearby, apologizing and explaining that her ordeal was meant to be spiritual and that Vilmer needed to be stopped for the ritual to proceed. He offers to ensure her safety and drops her off at a hospital, where an officer speaks to her. In the final moment, a blonde woman is wheeled on a gurney, and Jenny’s gaze meets hers, hinting at the larger reach of the killers’ network. Back on the dirt road, Leatherface remains in torment, flailing his chainsaw as the night closes in around him.
