Why is his dolphin acting so strangely? Something must be wrong. It is
the year 2013, and Robby lives in an Underwater Research Station with
his scientist parents. Most of the time he has fun exploring the ocean
caves with the dolphin who is his favorite companion. But something has
frightened the dolphin, and Robby sets out to investigate. Then he finds
the giant footprints. And he knows that something enormous and unknown
is walking here across the bottom of the sea.