Book One of the Accedence Cycle. Inspired by the Inheritance Cycle.

Once upon a time, in the magical land of Equestria, the peace of the land was maintained by a trio of magical beings called Alicorns. As beings of immense power - exemplifying the best traits of the three pony races: Unicorns, Pegasi and Earth Ponies - the three of them could keep at bay the beasts from beyond the Equestrian borders. There was a lasting peace.

Until one fell to darkness. He lost his beauty, his sanity and his conscience.

Nopony knew why it happened. The other two fought to subdue their warped, corrupted comrade, but in his insanity, he had broken the rules set in place by the three. By doing so, he had gained power over reality itself. So they fled, living to fight another day.

A thousand years passed, and many forgot the fall from grace. All they know is the tyrannical, insane rule of the King of Chaos, Discord.

And now, on the eve of the Thousandth Year, a young unicorn mare named Twilight Sparkle makes a discovery that will change the fate of Equestria forever.