On a rainy fall day, five friends descend into a remote Kentucky cave looking for adventure. Jesse, a rugged outdoors man and Ken, a socially-awkward film student, devise a plan to follow a series of instructions written in Jesse's family Bible rumored to lead to a trunk full of documents and old Confederate money. Ed and Sam, two friends of Jesse's are skeptical, but eager for the adventure. Jesse's girlfriend Julie is also dragged along. Ken intends to put the whole thing on video as a documentary film project. Once inside the cave, Jesse and Ken lead the group deep into a maze of underground passages. At first their confidence is infectious and the group marvels at beautiful flowstone formations and awe-inspiring stalactites and stalagmites within the cave. As the day wears on, however, Sam and Julie begin to tire of the expedition and worry about getting out safely, given the rising storm water and the complexity of their path.