The energetic quintet of pygmy dinosaurs of Prehysteria! return. After they escape from their pen and leave the farm where they first hatched, they blunder into a raisin shipment and end up sent to the home of rich but lonely boy Brandon Wellington. He shares his newest "toys" with his tomboy neighbor Naomi (Jennifer Harte). Trouble and hilarity ensue in this Jurassic comedy for all ages.