The mane 6, once Equestria's sworn protectors, become bringers of dark magic: demons.

[Bittersweet]
Dear Luna,

I was your hero.

And I failed you.

Is that why you haunt me?

Princess Celestia, after hundreds of years since Nightmare Moon was exiled, writes a letter to Princess Luna, in hopes of getting though to her, in bringing her little sister home. But it's rather hard to send a letter to the moon…

*Hit the top charts on the 7th of July, 2014!*