Adam is determined to find evidence of the existence of big cats that have been reported over the years in remote areas of South West Scotland. He convinces his best friend Mark to go with him and after an overnight stay at a country commune, they are joined by two girls, Marina and Summer, with the commune leader Phil agreeing to act as their guide. As they set off across Dungeon Moor, there is talk of a Polish girl who recently disappeared and a scientist working on a secret project in an isolated farmhouse. It becomes clear that Phil is leading them on a journey where their lives are endangered by something more than roaming big cats. Gripped by the thrill of danger and enjoying the developing sexual tensions in the group, Mark and Adam ignore warnings and their rural adventure turns into a nightmare.