Huey, a young ex-pilot, inherited the old mansion of his deceased bibliomanic grandfather and with it the book collection stored in there. However, there was one condition: he also had to inherit the "Bibliotheca." When he inspects the mansion, Huey discovers a cellar that is filled with piles of books. In the middle of these books he comes across a black-dressed girl who is silently reading a book. She is called Dalian and has a big lock hanging before her. She herself is the gateway to the "Bibliotheca Mystica de Dantalian," which contains the prohibited "Phantom Books."