There is a nursery rhyme that has made its way in various forms through Equestria's history, featuring three little fillies, a wicked wizard, and a dark mirror. But the passing of the centuries have a way of obscuring the true story, and the events that gave rise to this simple but eerie poem have been shrouded in the mists of time.

But in another world, they wait. They resent. They remember. And they, at least, will never forget.

Set in the TAS continuity, but can stand on it's own.

This story is a sequel to A Few Days Prior

A mere day before the beginning of the inter-school Friendship Games competition, an oblivious Aria Blaze takes a lunch break at the mall, and finds herself seated with a disgustingly cute and quirky couple. She's already had a bad day, but whether she ignores or interacts with them, they seem to find some way to make it even worse. It only devolves from there.

(Sex tag is for some crude language and discussion from a certain Siren)

When the three new students arrived and proposed the Battle Of The Bands, they attracted suspicion from Sunset and her friends, but they were prepared to deal with that. What they didn't expect was that their song affected another student more deeply than they could have forseen, and now she's found them. As magical battle erupts around her, Trixie just wants to know if she's rooting for the right side.

And Adagio Dazzle is all too willing to give her the answer she wants to hear...

Well into the modern age, Researchers, Historians, and Crackpot Theorists alike have remained baffled by the mysterious circumstances surrounding the disappearance of Clover The Clever. Indeed, the only one who could know what happened to that bright unicorn is Clover herself.

(More bittersweet than sad, but close enough)

Nopony was there to help her. She’d taken the shift alone, despite all the rumors. She’d dismissed them as pure nonsense – and now she was to pay for it with her life...

Before the Power Ponies came along, Maretropolis was a second Tartarus, as one ordinary mare is about to discover. But the more you push, sooner or later, something has to give...

Twilight wasn't prepared for this. Nopony was, really. When a strange city with stranger inhabitants suddenly reappears in the frigid north, Twilight and her friends, along with Princess Cadence, are sent to investigate these crystal ponies and attempt to open friendly relations with Equestria. But between competing with other nations' envoys, trying to make friends with the aloof, apathetic inhabitants, and investigating the causes for the city's reappearance in the first place, they have their work cut out for them...

AU tag because this is most assuredly not canon.
Emeral Bookwise and HiveLordLusa both deserve thanks for their huge help with this!

“But there is something you should know, Queen of the Changelings. You haven’t hurt me or my people half as much as you’ve hurt your own.”

"So the question you must ask yourself now," The princess concluded, "Is what you intend to do about it?"

Cover made by the very awesome Conicer. Go thank him!

Twilight stands in an empty, frozen Canterlot Castle. She's freezing to death, but she dares not move an inch, for fear of failing the test.