The Mystic Archives of Dantalian (ダンタリアンの書架 Dantalian no Shoka) or Bibliotheca Mystica de Dantalian is a light novel written by Gakuto Mikumo and illustrated by G-Yuusuke with 8 volumes and 35 story arcs, excluding special chapters.
It was serialized by Kadokawa Shoten from April 2008 to April 2011 in The Sneaker (ザ・スニーカー Za Sunīkā), a Japanese light novel magazine. The complete volumes were released by the same company between November 2008 and July 2011.
The light novel was adapted into manga and anime. A 9th volume was planned as a special issue in January 2012, but it was cancelled. Usually, there is at least one illustration per chapter. The chapters are labelled with an episode number, indicating its position in the series chronology. Each volume has 280 pages, on average. The last pages have the author's notes. As seen in its adaptations, it shows moments of mystery and suspense, with occasional comical situations caused by the exchange between the dual protagonists. Elements of fantasy happen when the characters interact with the Phantom Books.
Hugh Anthony Disward inherits the old mansion of his late grandfather with one condition: he must take over The Mystic Archives of Dantalian, or Bibliotheca Mystica de Dantalian, the Library guarded by an apparently young girl called Dalian. Hugh must act as her key-keeper and solve the cases involving Phantom Books, books that provide its reader with the power of demons.
During its publication, The Mystic Archives of Dantalian was featured three times in the cover of The Sneaker magazine, always with an illustration of Dalian. The first time occurred in 2009, during the chapters corresponding to volume 4. After that, the series was featured in the August 2010 issue cover, with chapters that later would be part of volume 6. This time, Flamberge and Rasiel were also shown, next to Dalian. The latter appears in the cover of the second to last issue, before the magazine ceased publication in April 2011.
The Mystic Archives of Dantalian is compared with the Gosick series, also published by Kadokawa Shoten. Both are set in Europe after World War I and have dual protagonists, including a rude girl with a doll-like appearance that spend her days reading difficult books and that eventually shows a warmer side.