The group of cavern tour guides includes four individuals: Sarah (played by Kelly Pantaleoni), her boyfriend Matt (played by Jeff Fahey), Sarah's best friend Mindy (played by Joey Kern), and Mindy's boyfriend Jared (played by Brent Briscoe). They all work at the local cave, taking groups on tours and showing them the stunning formations and underground rivers.
One day, while taking a break, they overhear an old man talking about a sacrificial cult that used to perform rituals in the cave. They are skeptical at first, but their curiosity gets the best of them, and they decide to sneak down to the restricted areas of the cave to investigate.
As they explore deeper, they begin to uncover strange symbols on the walls and an eerie feeling overtakes them. Suddenly, they accidentally summon a demonic presence that seems to be connected to the sacrificial cult. The demon refuses to let them leave and begins to terrorize them as they try to find a way out.
The group of guides must rely on their skills and knowledge of the cave to stay alive and outsmart the demon. As they struggle to survive, they realize that their curiosity may have unleashed something far beyond their understanding, and that they may not make it out alive.
