Littlefoot and his friends are being bullied and browbeaten by three dinosaurs: Hyp. Nod, a Nodosaurus. And Mutt. However, when a shower of meteorites (flying rocks) affects nearby the Great Valley and induces a stone slide from the Mysterious Beyond, that blocks the water supply of this Great Valley, Hyp, Nod, and Mutt aren't the biggest worry of Littlefoot and his buddies. The increasing lack of water causes conflicts between the inhabitants of this Great Valley, who've lived in peace and stability until this occasion.