While camping on a mountain, Mater meets a group of investigators searching for "Bigfoot" due to supposed sightings in the mountain. After Mater agrees on behalf of both himself and Lightning to join them, the duo accompanies the group on their search. Lightning is carnapped in a shack tied up from ropes by the purported "Bigfoot", whom he discovers is actually Ivy, a monster truck who ran away to the mountains due to feeling uncomfortable smashing cars as a performance. Mater finds them at Ivy's shack, and the two agree to scare off the investigators by pretending to be aliens. The next morning, Ivy joins the duo on their road trip. (thetvdb.com)