The Pteranodon family rides the "Night Train" all the way back to the Jurassic Period to visit their nocturnal friend, Vlad Volaticotherium, who tells them that he wants to take them caving! Buddy, Tiny, Shiny and Don don't even know what caving is, but they are soon having a great time seeing all the beautiful stalactites and stalagmites that have formed inside the cave.