The film takes place in a remote cave system, where a group of friends, including a geologist, a thrill-seeker, and a couple, venture into the depths of the earth. As they explore the cave, they start to experience strange occurrences and unsettling noises. It becomes clear that they're not alone, and a sinister presence begins to hunt them down. The group must work together to uncover the secrets of the cave and survive the night.