Ten years prior the city of Fuyuki was devastated by a fire that resulted from a disastrous Gas Explosion, claiming over Five-Hundred innocent souls before being extinguished.

Unbeknownst to the general public, however, the true cause of the disaster was no mere gas leak, but the catastrophic climax of a secret Ritual that had been held in the town for almost Two-Hundred Years.

Now, ten years later, Seven Masters once again converge on Fuyuki, hoping to lay claim to their deepest desires, even if they have to step over an army of corpses to do it.

Not if Sunset Shimmer has anything to say about it.

As Celestia's personal student, there was no doubt in Sunset Shimmer's mind that she was the most powerful Unicorn in Equestria. There was no spell she couldn't master, no lesson she couldn't learn...save for one.

Hoping to rectify the situation, Princess Celestia broke one of her own rules and unearthed Starswirl's Mirror, hoping that, by gazing into it, Sunset would see what she always wanted. Unfortunately, the plan worked a little TOO well, but not in the manner she hoped.

Cast out and believing herself betrayed by Celestia, a desperate Sunset decides to seek out her 'Hearts Desire' on the other side of the Mirror...to a place where she will learn the lessons Celestia so desperately wished for her to learn: that Friendship is Magic.

There was no doubt in Sunset Shimmer's mind that as Celestia's personal student she was the most powerful Unicorn in Equestria, bar none. But between the arrival of 'Princess' Cadence and Celestia's dismissing her for prying too deeply into Starswirl's Mirror, you can hardly blame her for being a little desperate.

Now trapped in another world in a form not her own, she'll be forced to learn the hardway the lessons Celestia so desperately wished for her to learn. Fortunately, there's more to her new friends than meets the eye.

Why do people talk about the The Trousers of Time when the daft bugger never actually wears them? No-one wears them, you simply fall continually into the waistband, not knowing from which leg you'll come out of.

In one universe, Rincewind, the Discworld's worst Wizard, chose not to speak the words of the Spell in his mind and found himself falling down one leg, which would lead to him going on many adventures quite against his will.

What would've happened if he'd fallen down the other leg?