It's over.
The Nightmare is finally over.

There are some things you cannot take back.
The wounds of Eternal Night cut deep in Equestria, in no one more than Celestia herself. Reeling from the painful aftershocks of betrayal and war and grief, Celestia is unraveling. But falling apart now is not an option. Equestria has lost one Princess, it cannot lose the other. There is work to be done, and The Princess of the Day must take on her sister's mantel if they are to survive.

Raise the Moon, Celestia, before the Darkness consumes you...

Shipping in an assistant librarian from Manehattan to run the Canterlot Archive is an unorthodox move to be sure, but Page Turner, fresh off the train, thinks that maybe it's just a sign that she's moving up in the world. Page is crushed when her duties in charge of the prestigious library turns out to be an endless parade of busywork.

But soon Page finds things are not quite as boring as she thought. She receives odd requests for the rarest spell books, and royal visits almost daily. Just when things seem to be looking up Page finds herself plagued by sleepless night, strange noises seeping from unseen corners, and vivid, frightening dreams.

All alone on her first time away from home, Page slowly puts together the pieces of a frightening truth:
Something is terribly wrong in Canterlot...

Dear Princess Dear Celestia,

Today I learned that sometimes how you say something can be just as important as what you have to say. It's easy to forget the true strength of words and all the subtle ways they can bring us closer together or push us apart. It doesn't matter if you're a filly in Ponyville or an Alicorn Princess in Canterlot, words are powerful.

There's still so much to learn about friendship. But I think I'm ready to start.

Your Faithful Student,
Your Friend,
Twilight Sparkle

On a cold winter's night after Hearthswarming, Twilight Sparkle comes to Celestia with evidence of a terrible historical conspiracy. Celestia responds by teaching her what it means to be remembered.