This is the official Storyline for Ecco the Dolphin: Defender of the Future taken from the manual of the Dreamcast Version.
At the dawn of the 30th century, after five hundred years of unity and fellowship, dolphin and man set out from the Earth to explore the great unknowns of space.
But where man and dolphin founded a civilisation of peace, others based theirs on strength, conquest, and domination.
And, even as man and dolphin went out from the Earth, a sinister Foe cast envious eyes upon it.
For the Earth was a prize beyond measure, a pristine world to be cherished or exploited.
But the Earth was not defenceless. The mighty Guardian - the greatest creation of the dolphin kind - shielded it with its power.
Undeterred, the Foe persisted, probing for a moment of weakness they were certain must come.
It was in this time that a dolphin named Ecco arrived at the Isle of the Guardian, seeking to learn from the scholars of peace, but destined to be the only hope and champion of the Earth.