Littlefoot, Cera, Spike, Petrie and Ducky resurface in an enchanting all-new musical story about the wonders of discovery. When heavy rains create a mysterious "new water," Littlefoot sets off to explore the Great Valley. He quickly becomes friends with Mo, a prank-playing dolphin-like creature who can't find his way back to the Big Water. Littlefoot and his prehistoric pals come to the rescue, evade a scary sharptooth and prove the value of courage, friendship and diversity in this exciting new adventure!