Sixteen-year-old Harper has decided to run away from home after she has another blow-out argument with her mother. Her two best friends, little sister, and ex-boyfriend stage an intervention disguised as a road trip to stop her from hitchhiking her way up Route 80 in Wyoming. What they don't realize is that Harper has been marked by a unique serial killer who's been trolling the highway for the past three years. Now the killer is after all of them, and they are thrust into an explosive, pulse-pounding and terrifying race for survival down the interstate. As the body-count rises, Harper will break all the limits to bring the killer down.