A group of young adults – Oscar and Karen, Beth and her marine infantry boyfriend Randy, and the latter's sister Emily and her boyfriend Niles, who is an ex-Navy SEAL – are traveling through the backwoods town of Fort Collins, Louisiana, when they pull over at a rundown gas station. While there, Oscar discovers a shrine to local legend, Lockjaw. The townies give the boys directions to a house built by "Grimley" himself, a local tourist attraction that they are hesitant to explore, only Oscar and Beth seem interested and convince the others to go with them. En route, Oscar tells them all the legend of Lockjaw: