Twilight Sparkle receives a new shipment of books ready to be stored within her library. She inspects them all each and every time, making sure every book is top quality and corresponds to what she has requested. However there's one among them that wasn't on her list. At the same time, the Tree of Harmony goes missing, leaving the growth of the Everfree Forest unchecked. To get it back, she must use the book to venture into the lands of Lothric and take back what was Equestria's.