For centuries, the Crystal Mountains has been a natural frontier for the northern border of Equestria, protecting the pony kind from the world beyond it. A world completly unknown.

Long ago, something from that world came to Equestria. Groups of a strange race of apes landed in the coast with their ships to loot and kill everything at their sight. For decades the pony kind suffered the attacks of these tall monsters full of rage and searchers of glory, they were known as......humans.

But one day they stopped coming, and during centuries ponies took their stories as myth, as something that ever existed or really happened.

Until a princess of the sun finds a crib with something inside....