Letting her doubt and fears get the best of her, Sunset Shimmer delves into forbidden magic, written by the famed though insane Starswirl the Bearded, she pierces the veil between worlds seeking power but finding a new purpose forced onto her. While some setbacks may prove more advantageous than at first thought, her actions allow a ancient evil to gain a foothold in his war against the light and in particular Celestia. Two strange creatures are born of this chaos, one in frozen darkness and the other in blinding light, with fates intertwined, they will come to shape the battle that will tear Equestria to its core.

Set in an alternate universe fifteen years before the thousandth Summer Sun Celebration.