The Monster Hunters are on a new assignment to investigate strange sightings of Big Muddy and UFO's in Murphysboro Illinois. It doesn't take long before the Robertson's come face to face with various elementals while lodging at the O'Learys cottage. Meanwhile after extensively tracking Big Muddy deep in the Shawnee National Forest they stumble across the legendary Burrows Cave where they find remnants of artifacts of ancient civilizations. Could all the strange occurrences be interconnected or is something entirely different?