I have heard ponies say that living so long would be a curse. That it is a burden. That it can break a pony's mind. There is some truth to that, but it's not the whole truth.
Ant Mill is a college student, stuck in a dead-end internship she took just to fulfill her requirements. All she does is wish she was somewhere else, but when she has a chance encounter with the Princess of Friendship herself, all that changes.
"When I read their letters... I think about how temporary everything really is." A lonely princess pores over her studies in a frigid castle, desiring nothing more than the warmth of an old friend.
Celestia reunites with her former student over tea after a forty-year vacation spanning the world, only to find that Twilight has changed quite a bit more than she expected.
The night that Cadance discovered the ghost of King Sombra lurking in the Crystal Palace should have been the worst of her life. Her greatest enemy is now lingering in her own home... and she knows that she's going to get to the bottom of this.
Princess Luna disappears from Equestria with hopes of saving the world and is accompanied by the enigmatic Sombra. Meanwhile, Celestia tries to bury secrets as immortal as she is and Cadance must choose her loyalties carefully...