Twilight Sparkle is called away to tend to Luna when she falls ill. As Luna grows sicker and Twilight more determined to help the younger princess, she begins to uncover dark secrets about the elements, the alicorns, and her own past.
Valiant has gone off on his own. An ancient evil has awakened on the far side of Equestria, nearby Valiant's destination, and threatens to devour him: body, mind, and soul. Can the combined might of the Elements of Equestria get to him in time?