While exploring the ruins of the Castle of the Two Sisters, Twilight finds something dark and not of this world. Some things don't know when to stay dead.
Luna's mind is fractured, broken. If she is going to return as a princess of Equestria, she needs time to heal, as much as she can. But who is going to help her heal, and who will she be at the end of it all?
Twilight gets a lucrative invitation for a top secret project. It seems like a dream come true, a true opportunity to help civilization advance, but soon the dream becomes a nightmare.
Twilight fights against sinister manipulations, struggling to overcome a deep-seated darkness within. As she battles to preserve everything she cares about, she will sacrifice anything necessary to succeed. But the price of victory may be herself.