This story is a sequel to Epiphany
Twilight has come back to the human world to visit Sunset Shimmer after having been away for a few weeks attending to things in Equestria. However, it turns out that she is greeted by a very tired, worn out, and obviously sick Sunset Shimmer. Twilight mentions having found a book at the Canterlot High library and Sunset asks Twilight to read to her.