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.
Not long after her release back into the general population of Ponyville, Screw Loose vanishes without a trace. During a search of her home one week after she was last seen, a video recording of her apparent final hours is found.