There's an old saying among ponies: Be careful what you wish for, because you just might get it.

In the aftermath of Tirek's rampage, Celestia finds herself thinking upon her life and yearns for those moments of glory and adoration from her youth. While on a trip to the Crystal Empire to assist Cadance and the other princesses in repairing the damage done by Tirek, Celestia finds herself drawn through the magic mirror into another world. Stuck with no way to return or communicate, she is forced to rely on the kindness of her newfound allies. But even here, dark shadows loom that threaten all...