Life was an adventure for Ecco, the young dolphin. The ocean seemed endless, with rolling breakers to race through! At high speed, Ecco could burst through the waves, leaping through the air - almost flying! Then, with a deep gulp of breath, Ecco would plunge down into the blue depths, where Shelled Ones hid in the coral crannies on the ocean floor.
Ecco knew that dolphins couldn't breathe underwater. Fish and coral stayed below the waves. But Ecco's kind needed air. This was a puzzle, and Ecco wanted to learn the answer.

The ocean was full of songs. There were easy ones that came to Ecco naturally. These were the songs for calling dolphins and other singers of the watery world. There were new songs that took time to learn. These songs could open the Shelled Ones and scare off the Hungry Ones who roamed near the dolphins' home. And then there were songs about just being alive and free!
The dolphins also had sad songs about stinging jellyfish, swift currents and rocky walls that trapped singers deep underwater. But the best ones were the proud, powerful songs about teeming schools of fish that filled the oceans and were good to eat, and about submerged, air-filled caves where a smart dolphin could breathe.

Five bright marks shone on Ecco's sleek head. No other dolphin had these silvery spots. When the air was dark, the family would sing that Ecco's markings matched five shining points far up in the sky. The song said that Ecco was special, a favorite of the ocean. Or maybe, it went on, the markings were just for looks, the way some fish had spots.
But the broad sky of the dry side also held a hidden terror. One day it attacked, without warning - a huge gust of swirling wind like a churning whirlpool of air and water. It tore all life from Ecco's Home Bay. Singers and Shelled Ones and even the small fish were ripped, helpless, twisting in fright, into the high nothingness beyond. And then they vanished!

Only Ecco remained. In the flash of one leap, Ecco's safe home, full of life and song, had become strange and silent. Everything had changed.

Now Ecco must fight to stay alive. Deadly hazards fill the wide oceans outside, but Ecco must find the lost dolphin pod. From the rip tides of the southern gulfs to the frozen chill of northern seas, Ecco must search through sunken worlds where razor teeth and poison stingers lurk in the dark depths.