While cruising through the woods in a ?borrowed? police car, PJ and Sam accidentally hit what looks like a mutant gorilla with a bad attitude. But this is no ape?it?s a goblin, escaped from the city of Argh in UnderEarth, a place beneath the world?s surface. When Sam is captured by a gang of goblins, PJ must go after him. But can PJ save Sam before he becomes dinner for a bunch of hungry goblins?