Arrrrgh!Get ready for an adventure featuring the most ferocious, savage, and slightly stupid, creatures under the earth!Cruising through the woods in a borrowed police car, teenage PJ and twelve-year-old Sam accidentally run down a bizarre creature. When Sam's curiosity gets the best of him, he crawls down its tunnel and is quickly captured by a mob of the ferocious beasts. PJ reluctantly goes underground after him, teaming up with a group of mysterious humans who have kept the creatures from discovering the surface of the earth for centuries, until the boys royally messed it up! Now both boys must use all of their ingenuity, and learn a few lessons, to escape the treacherous underground land and save the world!