Tyler, a keen film student, becomes obsessed with the horror movie The Hills Run Red, infamous for its ruthless killer known as Babyface and for a director, Wilson Wyler Concannon, who vanished years ago and left no known copy of the film. This fixation consumes Tyler, straining his relationship with his girlfriend, Serina, who soon starts an affair with their close friend, Lalo.
Driven by a mix of curiosity and passion for the lost film, Tyler discovers that Concannon’s daughter, Alexa, works as a nightclub stripper. He seeks her out to learn more about the project, and what begins as a tense encounter evolves into something more intimate when Alexa gives him a nude lap dance and later brings him back to her home. There, Tyler forcibly insists on hearing what she knows about the missing movie, and Alexa suggests that the film might actually lie hidden in her father’s secluded house in the woods.
Accompanied by Serina, Lalo, and Alexa, Tyler drives to the director’s house. Along the way, he confesses to Alexa that he believes Serina and Lalo are having an affair, and in a moment of vulnerability about his devotion to the film, he and Alexa share a kiss. The journey turns perilous when they are intercepted by rednecks they had interviewed earlier. The attackers threaten Alexa and Serina, but Babyface suddenly appears, eliminating the threats and pursuing the group into the forest.
Inside Concannon’s home, Tyler discovers a startling chamber—a red room draped with hanging film reels—where the truth about the movie and its creator begins to unfold. He also rescues Alexa, and the group reunites with Serina. However, Babyface ambushes them again, subdues Tyler, and captures Alexa as Serina narrowly escapes. It soon becomes clear that Alexa was herself orchestrating events, having paid off the rednecks to manipulate the situation.
As Alexa accelerates her plot, Serina uncovers brutal evidence in a makeshift smokehouse—the grisly remains of those who crossed their path. Babyface drags Serina back into danger, while Tyler, waking, finds himself strapped to a wheelchair surrounded by reels of The Hills Run Red and confronted by Concannon, who reveals the grim secret behind the “scares” that defined his film. Twenty years earlier, Concannon grabbed Babyface’s costume from the original actor and brutally killed that actor; since then, he has killed each actor by turning their on-screen deaths into real carnage. He also discloses that Babyface is his son, born from an incestuous relationship with Alexa after Concannon’s wife died and he raped Alexa when she was only thirteen. Babyface has since decades sculpted his visage into the horror icon, masking his mutilated face to honor his father’s twisted legacy.
As Concannon speaks, Alexa begins filming her own movie as she tortures Lalo in the barn, while Babyface exacts vengeance on his own father. When Serina escapes a moment, Alexa shoots Concannon, enraging Babyface enough to turn on his father in a ferocious clash. Tyler seizes a camera and manages to sway Babyface to turn on Concannon as well, but the psychopath killer then targets Tyler. Serina intervenes, and she stabs Babyface through the back with a long iron staff, killing him. Alexa, infuriated by her son’s death, recovers and overpowers Serina and Tyler, forcing Tyler to watch as she continues editing and cutting together her version of The Hills Run Red, thanking him for awakening her potential as a director free from her father’s control. The battered trio is left bound as the looped film continues to replay, and Tyler, bleeding out, slowly laughs through his gag as the nightmare persists.
In a mid-credits scene, Serina remains Alexa’s prisoner and is revealed to be several months pregnant with Babyface’s child. Alexa reappears, carrying Babyface’s mask as a chilling gift for the future grandchild, and she sings a lullaby to the unborn child while Serina’s screams echo, signaling that the cycle of fear and control may endure beyond the events of the film.
