Littlefoot and his friends are being bullied and browbeaten by three teenage dinosaurs: a Hypsilophodon, Hyp. Nod. And Mutt, a Muttaburrasaurus. However, when a shower of meteorites (flying rocks) affects nearby the Great Valley and causes a stone slide at the Mysterious Beyond, that blocks the water supply of this Great Valley, Hyp, Nod, and Mutt aren't the biggest concern of Littlefoot and his friends. The increasing lack of water causes battles between the inhabitants of this Great Valley, who have lived in relative peace and harmony.