Two university students, Pahoo and Rives, travel to a small Louisiana town to investigate reports of a mysterious creature rumored to inhabit the surrounding swamps. Their college professor, intrigued by the legend and previous sightings, encourages their field research. Upon arrival, they encounter the local sheriff who is dismissive and warns them not to stir trouble. Unfazed by the sheriff's attitude, the two aspiring researchers set up camp near Black Lake to begin documenting evidence of the creature. As they delve deeper into the dense woods, they meet an array of quirky townsfolk, including the eccentric gas station owner Orville and the grizzled trapper Joe Canton. Though initially skeptical, Joe reveals his own encounter with the creature, lending credence to the students' mission.

As they immerse themselves in local folklore, strange occurrences escalate at their camp. Nocturnal disturbances, disembodied sounds, and fleeting glimpses of a large, shadowy figure confirm that something lurks in the wilderness. The students' skepticism turns to belief as they collect audio tapes and footprints that hint at the beast's presence. However, their relentless pursuit is met with growing hostility from both natural and human elements. As their investigation intensifies, tensions rise between curious expeditions and the uneasy locals, culminating in an unexpected confrontation that tests their resolve and commitment to uncovering the truth about what lies hidden in the swamp.