Picking up after the events of the original film, the people of Newt, Texas, led by Mayor Burt Hartman (Paul Rae
), burn down the farmhouse of the Sawyer family for their role in aiding Jedidiah "Jed" Sawyer (Dan Yeager
), also known as "Leatherface", in several murders. The arsonists are celebrated as heroes in the town, and the entire family is presumed dead. However, an infant, Edith Sawyer, is found by one of the townsmen, Gavin Miller (David Born
), who promptly murders her mother, Loretta Sawyer (Dodie Brown
), and adopts Edith with his wife Arlene (Sue Rock
). Decades later, Edith has been raised by Gavin and Arlene as Heather Miller (Alexandra Daddario
). One day, Heather is notified that her grandmother, Verna Carson (Marilyn Burns
), has passed away and left everything to her; discovering that she was adopted, Heather and her boyfriend Ryan (Trey Songz
), and two other friends, Nikki (Tania Raymonde
) and Kenny (Keram Malicki-Sánchez
), travel to Newt to collect her inheritance. Along the way, the group picks up hitchhiker Darryl (Shaun Sipos
When they arrive, the Sawyer family lawyer, Farnsworth (Richard Riehle
), gives her the keys to the family house along with a letter from Verna. Farnsworth strongly admonishes Heather to read this letter immediately. Excited about the property she now owns, Heather and her friends look through the house, decide to stay the night, and immediately set off to buy supplies and food; Heather putting the letter aside to read later. She and her friends trust Darryl to stay and look over the house. But Darryl begins looting it and believes he will find valuables in a locked room in the cellar of the house; however, upon entering the locked room he is bludgeoned by Leatherface. Heather and her friends return and discover the house has been ransacked, but choose to let it go. As Kenny prepares dinner he finds the butler's cellar, where Darryl was killed, and Leatherface impales him on a hook. Heather finds a decomposing body upstairs and runs to find her friends, but she is knocked unconscious by Leatherface. Waking up in Leatherface's room, she manages to escape to the graveyard. Hearing the screams and chainsaw, Ryan and Nikki draw the attention of Leatherface, while Heather gets their van and picks up her friends.
In the ensuing chase, Leatherface saws through one of the van's tires, causing it to crash and subsequenly kill Ryan. Heather escapes and makes her way into a carnival, but Leatherface escapes the police who are patrolling the grounds. Sheriff Hooper (Thom Barry
) realizes that Leatherface survived the fire and is still alive; Mayor Hartman sends Officer Marvin (James MacDonald
) to the Sawyer house to kill Leatherface, against Hooper's orders. While looking for Leatherface, Marvin is startled and accidentally kills Nikki, before being killed by Leatherface himself. While at the station, Heather reads some old case files left with her, and learns of what the townspeople did to her family. She writes 'murderers' across a photo of the celebrating townspeople, and flees. She is soon caught by Hartman's son, Deputy Carl Hartman (Scott Eastwood
), who ties her up at the long-abandoned Sawyer slaughterhouse to lure Leatherface. Once there, Leatherface advances on Heather to kill her, but sees her 'birthmark,' which her real mother made by pressing a necklace with the family symbol into Heather's flesh when she was a baby. Realizing Heather is his cousin, Leatherface frees her, but is attacked by Mayor Hartman and another officer, Ollie (Ritchie Montgomery
As Heather hears her cousin being beaten she decides to help him, killing Ollie with a pitchfork and giving Leatherface his chainsaw, which he uses to force Mayor Hartman into a meat grinder. Sheriff Hooper, who'd never condoned the slaughter of the Sawyer family, watches stonily, and then lets Heather and Leatherface go; merely admonishing her to clean up after Leatherface.
Heather and Leatherface return home, where Heather reads the letter from Verna. The letter tells her of Leatherface's living arrangements, and that he needs a caretaker due to his mental state. If Heather takes up this task, he will protect her from any who would still wish the family harm. Realizing Leatherface is the only family she has left, Heather decides to stay with him.
In a post-credits scene, Gavin and Arlene show up at the mansion to see Heather, greedily seeking a share of her assets. As they wait by the door, Leatherface comes out with his chainsaw.