This movie puts Henk Ketcham's comic figure 'Dennis' into real life: While digging in his front garden, Dennis finds a big bone. To prove it's from a dinosaur, he persudades his father to invite an old buddy of him, Bowen Skyler III, who's a famous 'dinosaur hunter'. Being desperate for publicity, Skyler informs press and television... and starts a paleontologic dig in their front garden!