The film centers on a young woman, Penny, who has a phobia of cars and ends up stalked by a maniac hitchhiker preying on her fear.

[1] Penny, a young woman traumatized by a childhood auto accident that killed her parents, accompanies her therapist Orianna on a road trip to a mountain community as part of her therapy to overcome her fear of cars.

Penny is tortured for another few hours; and, when she tries to crawl out of the car window, the hitchhiker grabs her right foot and cuts off one of her toes.

After finally falling asleep, she turns around to find the hitchhiker sitting in the back wearing Orianna's clothes, who then pulls off the hood (revealed to be a demented female mental patient) and tries to strangle her while saying, "Don't forget your breathing exercises, Penny."

She manages to fight off the hitchhiker by stabbing her in the eye with a pencil and escapes from the car, only to trip from her injured foot.